Redox Flow Battery Electrode with Carbon Nanotube Composite

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Solution Overview

Problem

Redox flow batteries face limitations in electric capacity, cell resistivity, and pressure loss when using existing electrode technologies.

Innovation Solution

A redox flow battery electrode is created by laminating a conductive sheet with carbon nanotubes of specific diameters and a porous sheet, strategically positioned between an ion exchange membrane and a bipolar plate, to enhance electric capacity, reduce cell resistivity, and minimize pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a porous sheet material softer than the electrode material is provided between the ion exchange membrane and the electrode, then the electrode structure is protected, but the electric capacity and cell resistivity performance is insufficient

Engineering Contradiction:
Improveelectrode structure protectionVSAvoidelectric capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The electrode uses a composite structure combining carbon nanotubes (diameter 1-10 μm) with carbon fibers (diameter 10-50 μm) to create a multi-scale conductive network. This composite material approach achieves both structural integrity and superior electrical conductivity, resolving the contradiction between protective function and electric capacity performance

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If carbon fiber felt with voids is used as the electrode material, then pressure loss is reduced, but the electric capacity and cell resistivity remain insufficient

Engineering Contradiction:
Improvepressure lossVSAvoidelectric capacity
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The electrode implements local quality differentiation through a dual-component structure: carbon nanotubes provide localized high-conductivity pathways while carbon fibers create macroscopic void spaces. This spatial differentiation of material functions simultaneously reduces pressure loss through improved fluid flow and enhances electric capacity through optimized conductive networks

Inventive Principle:
Principle #3Local quality

3Device complexity

If the electrode uses a single material composition, then the structure is simple, but the cell resistivity and electric capacity performance is insufficient

Engineering Contradiction:
Improveelectrode structureVSAvoidcell resistivity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The electrode employs a composite material system combining two distinct carbon-based materials with different diameter ranges and functional properties. The carbon nanotubes (1-10 μm) provide high surface area and conductivity, while carbon fibers (10-50 μm) provide structural framework and void spaces, achieving low cell resistivity without excessive structural complexity

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 solution results in a redox flow battery with improved electric capacity, low cell resistivity, and reduced pressure loss, effectively addressing the limitations of existing technologies.

Implementation Method 1

the electrode is obtained by laminating a conductive sheet containing carbon nanotubes having an average fiber diameter of 1 μm or less

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a porous sheet formed from fibers having an average fiber diameter of greater than 1 μm

Methodology Applied
Scientific EffectFluid flow through porous material: Porosity

Data Source

PatentEP3240071B1Electrode for redox flow batteries, and redox flow battery
Publication Date: 2020.07.22 RESONAC HOLDINGS CORP
  • EP3240071B1 patent drawingFigure 1
  • EP3240071B1 patent drawingFigure 2
  • EP3240071B1 patent drawing

AI summary

A redox flow electrode according to one aspect of the present invention is a redox flow battery electrode disposed between an ion exchange membrane and a bipolar plate, wherein the electrode includes a conductive sheet containing carbon nanotubes having an average fiber diameter of 1 µm or less, and a porous sheet that is laminated to the conductive sheet and is formed from fibers having an average fiber diameter of greater than 1 µm.