Organic Superacid Proton Exchange Membrane for Low Humidity Fuel Cells

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Proton exchange membranes in fuel cells face challenges with proton conductivity at low relative humidity, leading to issues like cathode flooding, water management, and increased operational costs.

Innovation Solution

Development of an organic-based proton exchange membrane using a solid phase polymer material derived from organic superacids with high acidity and capable of intramolecular hydrogen bonding, which enhances proton conductivity by maintaining elevated solvated proton density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polymer electrolytes are used in PEM fuel cells, then the membrane provides basic proton conduction and structural functions, but proton conductivity deteriorates at low relative humidity conditions

Engineering Contradiction:

Improveproton conductivityVSAvoidlow relative humidity performance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure of acid groups within the polymer electrolyte by introducing superacidic groups with multiple proton-donating capabilities and specific spatial arrangements. This changes the fundamental parameter of acid strength and proton availability, enabling the membrane to maintain high proton conductivity even when environmental humidity is low, thus resolving the contradiction between reliable proton conduction and performance under low humidity conditions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite polymer structure incorporating multiple types of acid groups (sulfonic, carboxylic, phosphonic) with different pKa values and proton-donating characteristics. This composite approach combines the advantages of various acid groups to achieve synergistic effects, where the multifunctional superacidic groups provide enhanced proton conductivity that remains stable across varying humidity levels, addressing the reliability-humidity performance contradiction

Inventive Principle:

Principle #40Composite materials

2Reliability

If polymer membranes are designed to improve proton conductivity, then proton conduction pathway is enhanced, but water management issues and cathode flooding may worsen

Engineering Contradiction:

Improveproton conductionVSAvoidcathode flooding

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces acid groups with specific local spatial arrangements and orientations within the polymer matrix, creating localized regions of high proton activity. The multifunctional superacidic groups are positioned to optimize proton transfer pathways while their structured arrangement facilitates controlled water distribution. This local optimization enables enhanced proton conduction without creating excessive water accumulation that would lead to cathode flooding

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention utilizes the water-proton coupling mechanism by designing superacidic groups that can efficiently bind and manage water molecules. Instead of viewing water as a harmful substance causing flooding, the patent converts water into a beneficial component that facilitates proton dissociation and transport. The multifunctional acid groups strategically manage water to enhance proton conductivity while preventing harmful water accumulation at the cathode

Inventive Principle:

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

3Ease of manufacture

If conventional electrolyte materials are used, then manufacturing and operation are straightforward, but operational costs increase due to water management requirements

Engineering Contradiction:

Improvemembrane fabricationVSAvoidoperational costs

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent employs conventional polymer synthesis methods to create membranes with modified chemical structures containing multifunctional superacidic groups. These parameter changes in acid group functionality are achieved through standard polymerization and chemical modification techniques, maintaining ease of manufacture. The resulting membranes require less intensive water management systems and operational interventions, thereby reducing energy losses and operational costs while preserving manufacturing simplicity

Inventive Principle:

Principle #35Parameter changes

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 membrane exhibits improved proton conductivity at low relative humidity, reducing issues related to cathode flooding and water management, and potentially lowering the operational costs of fuel cells.

Implementation Method 1

an organic superacid that includes at least two acid groups. The acid groups may comprise a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, or any other acid group that may have a structure which promotes intramolecular hydrogen bonding

Methodology Applied

Scientific EffectIntramolecular hydrogen bonding: Hydrogenation

Data Source

PatentUS7718753B2Organic superacids, polymers, derived from organic superacids, and methods of making and using the same

Publication Date: 2010.05.18 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

One embodiment of the invention contemplates a proton exchange membrane for use in a variety of fuel cells. The proton exchange membrane may comprise a solid phase organic based copolymer material in which a first structural unit is derived from a polymerizable organic super acid. The organic super acid may comprise an acid group such as a sulfonic acid group or a carboxylic acid group.