Description:

INV-15071

Structures for Gas Diffusion Materials and Methods for Their Fabrication

A high-performing gas diffusion structure working in critical conditions of high temperatures and low oxygen

Background

The dominant generation of automotive drive systems in the future or efficient energy production in other fields relies on the invention of effective fuel cells and electrolyzers. Gas diffusion structures have increasingly gained attention as a promising solution for running fuel cells, electrolyzers, or many other electrochemical applications. A typical gas diffuser is composed of a porous current-conducting web coated with current-conducting layers. It is desirable to have a separate channel for water and gas transport with different hydrophobicity and porosity. Current gas diffusers are mainly consisting of two layers; the current-conducting coating layer constituting the gas diffuser region with hydrophobic property and the active zone with hydrophilic property, where catalysis happens and porosity may also be changed. Bilayer gas diffusers fail to meet gas/water transport at a sufficient level particularly in critical conditions such as high temperature or in low-oxygen mixtures. Therefore, we cannot rely on current gas diffusers to design membrane fuel cells operating at high temperatures (100°C or more) or electrolyzers for oxygen-depolarized aqueous hydrochloric acid electrolysis. 

This technology overcomes the current limitations of bilayer gas diffusers by optimizing gas and water transport. 

Technology Overview

Researchers at Northeastern invented a multi-layer coating gas diffuser, which provides a gradient of porosity and hydrophobicity. In this invention, the conducting web is coated by multiple layers having different compositions. Changes in at least one parameter of coating layers such as the carbon ratio provide a fine gradient of hydrophobicity and porosity, with the smaller size and more hydrophilic layers near the catalyst zone. This invention is more efficient than current gas diffusers since the porosity and hydrophobicity do not decrease suddenly between the gas diffuser region and the catalytic site. Multi-layer gas diffusers provide a robust platform for the highest operating temperature and better water management, which leads to the production of more energy-efficient, cost-effective, and simpler fuel cells. 

Benefits

• Gradient changes of porosity and hydrophobicity 
• Energy efficiency and High performance
• Better water management 
• Applicable in critical conditions such as high temperature or oxygen-depleted mixture 

Applications

• Fuel cell
• Membrane electrolysis 
• Other electrochemical applications 

Opportunity

• License
• Partnering
• Research collaboration