Protonated Dimeric Ionic Liquid for PEMFC Catalyst Layer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Polymer electrolyte membrane fuel cells (PEMFCs) face challenges such as high material costs, poor proton transport in varying humidity conditions, slow oxygen reduction reaction kinetics, and durability issues due to excessive water or dryness, leading to performance gaps and increased catalyst usage.

Innovation Solution

Incorporating a protonated dimeric ionic liquid, specifically 9′9′-(butane-1,4-diyl)bis(3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-ium) 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate, as a secondary ionomer in the catalyst layers to enhance proton transport and catalyst activity, stability, and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large amounts of catalyst are used to overcome performance issues, then oxygen reduction reaction activity is improved, but material cost substantially increases

Engineering Contradiction:

Improveoxygen reduction reaction activityVSAvoidcatalyst loading

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the chemical and physical parameters of the ionomer by using a protonated dimeric ionic liquid with specific molecular structure (9,9-(butane-1,4-diyl)bis(3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-ium) 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate) instead of conventional polymeric ionomers. This parameter change enhances proton conductivity and catalyst utilization, allowing reduced catalyst loading while maintaining or improving ORR activity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite catalyst layer combining metal catalyst particles with a protonated dimeric ionic liquid. This composite material integrates the catalytic function with enhanced proton transport capability, improving overall electrode performance while reducing the quantity of expensive catalyst material required.

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 protonated dimeric ionic liquid improves the oxygen reduction reaction activity and membrane electrode assembly (MEA) performance across a range of humidity levels, reducing high frequency resistance and proton diffusion resistance, thereby increasing power density and durability while lowering catalyst loading.

Implementation Method 1

superior proton transport capability under varying humidity conditions

Methodology Applied

Scientific EffectProton conduction: Conduction (electrical)

Implementation Method 2

improves the oxygen reduction reaction activity and membrane electrode assembly (MEA) performance

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS11731110B2Protonated dimeric ionic liquid to enhance performance of membrane assembly electrode (MEA)

Publication Date: 2023.08.22 TOYOTA JIDOSHA KK

AI summary

A protonated dimeric ionic liquid that enhances and improves the performance of a fuel cell catalyst. The protonated dimeric ionic liquid comprises 9′9′-(butane-1,4-diyl)bis(3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-ium) 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate. Membrane electrode assemblies (MEAs) and polymer electrolyte membrane fuel cells (PEMFCs) employing the protonated dimeric ionic liquid are also disclosed.