Catalyst Ink Manufacturing for Fuel Cell Electrodes

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Solution Overview

Problem

Catalyst electrodes in fuel cells face challenges in achieving uniform power generation distribution, durability, and gas permeability due to non-uniform catalyst ink dispersion and potential cracking, which affects the performance and longevity of the fuel cell.

Innovation Solution

A manufacturing method for catalyst ink involving the dispersion of catalyst-supported particles in a solvent, mixing with an ionomer and a volatile solvent to create a gel material, and adjusting viscosity through stirring and heating to produce a uniform, porous coating that enhances dispersibility and coating performance, thereby improving the structural integrity and gas diffusivity of the electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If catalyst-supported particles are dispersed in a solvent to form catalyst ink, then the coating performance improves, but the dispersibility and uniformity of the catalyst particles deteriorate due to aggregation

Engineering Contradiction:

Improvecoating performanceVSAvoiddispersibility of catalyst particles

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent introduces an ionomer as an intermediary substance that mediates between the catalyst-supported particles and the solvent. The ionomer wraps around the catalyst particles, preventing direct aggregation while maintaining dispersibility in the solvent, thus resolving the contradiction between coating performance and particle stability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure where ionomer and catalyst-supported particles form a combined material system. This composite approach allows the catalyst particles to maintain their dispersibility while the ionomer provides the necessary coating properties, simultaneously improving both manufacturing ease and material stability

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If the catalyst ink is dried to form a coating film, then the catalyst electrode structure is formed, but cracking and degradation occur on the electrode surface

Engineering Contradiction:

Improvestructural uniformity of catalyst electrodeVSAvoiddurability of electrode surface

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The ionomer serves as a cushioning agent that is applied beforehand to wrap around catalyst particles. During the drying process, this ionomer layer acts as a protective cushion that prevents the formation of cracks and degradation on the electrode surface, maintaining both structural uniformity and reliability

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The ionomer forms a flexible thin film around the catalyst particles and across the electrode surface. This flexible film accommodates stress during drying and prevents cracking, thereby improving both the manufacturing precision and the durability of the catalyst electrode

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If the catalyst ink has high viscosity for adequate coating strength, then the coating performance improves, but the gas permeability and diffusivity of the electrode deteriorates

Engineering Contradiction:

Improvecoating strengthVSAvoidgas permeability and diffusivity

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies local quality by having the ionomer distributed throughout the catalyst ink and forming localized regions around individual catalyst particles. This local distribution provides adequate coating strength where needed while maintaining open pathways for gas transport, thus improving both coating performance and gas permeability simultaneously

Inventive Principle:

Principle #3Local quality

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 results in catalyst electrodes with improved power generation performance, durability, and gas permeability, reducing the likelihood of cracking and enabling efficient mass production of high-performance fuel cells.

Implementation Method 1

When the catalyst ink produced by this manufacturing method is dried, it is contemplated that pore spaces surrounded by the ionomer are formed by volatilization of the volatile solvent surrounded by the ionomer in the gel material.

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

dispersing catalyst-supported particles as conductive particles with a catalyst supported thereon in a solvent to prepare a catalyst dispersion

Methodology Applied

Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentUS9865885B2Manufacturing method of catalyst ink, manufacturing method of fuel cell, and fuel cell

Publication Date: 2018.01.09 TOYOTA JIDOSHA KK

AI summary

A catalyst ink for improving the performance of catalyst electrodes in a fuel cell is produced by the following procedure. A catalyst dispersion is prepared by dispersing catalyst-supported particles as conductive particles with a catalyst supported thereon in a solvent. A gel material having viscoelasticity is prepared by mixing an ionomer with a volatile solvent. A catalyst ink having a desired viscosity is produced by stirring and mixing the catalyst dispersion with the gel material.