Fuel Cell Gas Diffusion Layer Vacuum Pre-Infiltration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for preparing fuel cell gas diffusion layers, such as hot pressing, can damage the carbon paper and reduce water vapor transmission efficiency, affecting the performance and durability of the gas diffusion layer due to poor contact between the microporous layer and the carbon paper.
Innovation Solution
A process involving pre-infiltration of a microporous layer slurry into hydrophobic carbon paper using vacuum adsorption to fill macropores and improve surface contact, followed by sintering at 250-400°C to enhance the interface contact and reduce pore size differences, thereby stabilizing the pore structure and improving water vapor transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hot pressing treatment is used to improve interface contact between microporous layer and carbon paper layer, then contact quality is improved, but structural damage occurs to carbon paper and water vapor transmission path is compressed
Solution Approach 1:
The invention applies preliminary action by performing vacuum infiltration treatment before the main coating process. The microporous layer slurry is pre-infiltrated into the carbon paper layer through vacuum adsorption, creating a transition zone that facilitates subsequent coating and eliminates the need for hot pressing treatment that would damage the carbon paper structure.
Solution Approach 2:
The invention uses an intermediary approach by introducing a transition zone formed through vacuum infiltration. This transition zone acts as an intermediary between the microporous layer and carbon paper layer, providing gradual pore size transition and improving interface contact without requiring direct high-pressure contact that would damage either layer.
2Ease of manufacture
If microporous layer slurry is directly coated on hydrophobic carbon paper, then coating process is simple, but contact area is insufficient and interface adhesion is weak
Solution Approach 1:
The invention applies preliminary action by performing vacuum infiltration treatment before the main coating process. The microporous layer slurry is pre-infiltrated into the carbon paper layer through vacuum adsorption, creating a transition zone that facilitates subsequent coating and eliminates the need for hot pressing treatment that would damage the carbon paper structure.
Solution Approach 2:
The invention uses pneumatic principles by applying vacuum pressure to achieve infiltration. The vacuum pump creates negative pressure that draws the microporous layer slurry into the carbon paper layer through capillary action, significantly increasing the contact area between layers without requiring mechanical pressure.
3Speed
If pore size difference between microporous layer and carbon paper layer is large, then gas diffusion is fast, but water vapor transmission path is disrupted and interface stability is poor
Solution Approach 1:
The invention applies local quality by creating a transition zone with gradually changing pore sizes at the interface between the microporous layer and carbon paper layer. This local modification ensures that each region has appropriate pore characteristics: larger pores in the carbon paper for gas diffusion and smaller pores in the microporous layer for water management, with a gradual transition in between.
Solution Approach 2:
The invention uses parameter changes by gradually transitioning the pore size parameter from the carbon paper layer to the microporous layer through the vacuum infiltration process. This gradual parameter change creates a stable pore structure transition that maintains both gas diffusion efficiency and water vapor transmission continuity.
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 approach increases the contact area between the microporous and carbon paper layers, reducing ohmic resistance and enhancing the durability and water vapor erosion resistance of the gas diffusion layer, leading to improved fuel cell performance and stability.
Implementation Method 1
moving the hydrophobic carbon paper coated with the microporous layer slurry to a porous ceramic plate, and connecting a vacuum pump to the porous ceramic plate, vacuumed for adsorption pre-infiltration treatment
Implementation Method 2
the microporous layer slurry was infiltrated into the hydrophobic carbon paper layer by using the vacuum adsorption force to overcome the capillary pressure
Implementation Method 3
then sintering at 250-400° C. to obtain a gas diffusion layer
Implementation Method 4
hydrophobic carbon paper
Data Source
AI summary
Disclosed is a membrane electrode, fuel cell gas diffusion layer, and process for preparing the fuel cell gas diffusion layer, the process comprising: S1 coating microporous layer slurry on the surface of hydrophobic carbon paper; the microporous layer slurry was obtained by dispersing mixture of carbon powder, polytetrafluoroethylene dispersion solution, thickener, and solvent; S2 moving the hydrophobic carbon paper coated with the microporous layer slurry to a porous ceramic plate, and connecting a vacuum pump to the porous ceramic plate, vacuumed for adsorption pre-infiltration treatment, and then dried. S3 continuing to coat the microporous layer slurry on the hydrophobic carbon paper dried in step S2, then drying, and then sintering at 250-400° C. to obtain a gas diffusion layer. The beneficial effects of this disclosure include: this disclosure improve the water vapor erosion resistance of the microporous layer and the durability of the gas diffusion layer.