Laminated Electrolyte Membrane for Solid Polymer Fuel Cells

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Solution Overview

Problem

Solid polymer fuel cells face challenges in achieving both high output performance and durability, particularly under low humidified conditions, as existing methods only provide slight improvements in output capabilities.

Innovation Solution

A laminated electrolyte membrane structure comprising a first layer with a relatively low ion exchange capacity and a second layer with a higher ion exchange capacity reinforced with a porous body, where the ion exchange capacity difference between the two layers is significant, enhancing both output performance and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ion exchange capacity of the electrolyte membrane is increased, then the proton conductivity becomes higher and the electric resistance becomes lower, but the electrolyte membrane tends to contain water and be easily swollen to result in significant size alteration and mechanical strength decrease

Engineering Contradiction:
Improveproton conductivityVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The electrolyte membrane is divided into multiple layers with different ion exchange capacities. The first layer (outer layer) has an ion exchange capacity of 0.8-1.0 meq/g, while the second layer (inner layer) has an ion exchange capacity of 1.1-1.3 meq/g. This segmentation allows different regions of the membrane to have optimized properties: the outer layer provides mechanical stability, while the inner layer provides high proton conductivity for improved output performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the electrolyte membrane are assigned different ion exchange capacities based on their functional requirements. The inner layer that contacts the catalyst layer is given high ion exchange capacity to maximize proton transport and output performance, while the outer layer is given lower ion exchange capacity to maintain mechanical strength and dimensional stability. This local differentiation resolves the contradiction between overall mechanical strength and localized proton conductivity.

Inventive Principle:
Principle #3Local quality

2Productivity

If the ion exchange capacity of the electrolyte membrane is increased to improve output performance, then the electric resistance decreases, but the membrane swelling and size alteration increase under humidified conditions

Engineering Contradiction:
Improveoutput performanceVSAvoiddimensional stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The membrane is segmented into outer and inner layers with different ion exchange capacities. The outer layer with lower ion exchange capacity (0.8-1.0 meq/g) maintains dimensional stability and resists swelling under humidified conditions, while the inner layer with higher ion exchange capacity (1.1-1.3 meq/g) provides the high proton conductivity needed for improved output performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner layer is specifically designed with high ion exchange capacity to maximize output performance where it is most needed (at the catalyst interface), while the outer layer maintains lower ion exchange capacity to provide dimensional stability. This local quality differentiation allows the membrane to achieve high productivity without sacrificing compositional stability.

Inventive Principle:
Principle #3Local quality

3Productivity

If the ion exchange capacity of the inner layer is increased without porous body reinforcement, then the output performance is slightly improved, but the mechanical strength and durability deteriorate

Engineering Contradiction:
Improveoutput performanceVSAvoiddurability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The inner layer is designed with high ion exchange capacity (1.1-1.3 meq/g) to maximize output performance, while the outer layer is designed with lower ion exchange capacity (0.8-1.0 meq/g) to maintain mechanical strength and durability. This local quality approach allows the high-performance inner layer to be optimized for productivity without compromising the overall reliability provided by the outer layer.

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

This configuration significantly improves output performance and durability, especially under high output operations in low humidified conditions, while maintaining high performance without significant deterioration.

Implementation Method 1

the ion exchange capacity of the ion exchange resin for the second layer is higher than the ion exchange capacity of the ion exchange resin for the first layer

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

second layer comprising a porous body and an ion exchange resin filled into the fine pores of the porous body

Methodology Applied
Scientific EffectPhysical reinforcement:

Data Source

PatentEP1998393B1Electrolyte membrane and solid polymer fuel cell
Publication Date: 2012.08.08 W L GORE & ASSOC GK
  • EP1998393B1 patent drawingFigure 1
  • EP1998393B1 patent drawingFigure 2
  • EP1998393B1 patent drawingFigure 3~4

AI summary

An electrolyte membrane for a solid polymer fuel cell according to the present invention is a laminated body of (1) a first layer 11 comprising an ion exchange resin and (2) a second layer 12 comprising a porous body and an ion exchange resin filled into the fine pores of the porous body and is characterized in that an ion exchange capacity of the ion exchange resin for the second layer 12 is higher than an ion exchange capacity of the ion exchange resin for the first layer 11. Consequently, both of output performance and durability can be achieved simultaneously at a high level.