Defects in hydrogen fuel cells
Researchers have established metal contamination that can cause hydrogen fuel cells to fail.
The team from Toronto Metropolitan University’s research could inform development of next-generation cells that are longer lasting and more efficient.
The Toronto team has reported that as the fuel cells operate, they get contaminated by tiny, positively-charged particles of metal – also known as metal cations – that can degrade their performance.
These particles can come from anywhere – impurities in the hydrogen, degradation of metal parts of the cell, or even the air.
They reportedly get in the way of the chemical reaction.
The team added cobalt ions to a fuel cell and used the ultrabright light of the Canadian Light Source (CLS) at the University of Saskatchewan to track their movement through a simplified version of a fuel cell, to figure out how exactly these cations behave in a fuel cell.
Using the BioXAS beamline at the CLS allows for the required speed to record the cations movements.
The measurements were reportedly collected at CLS to build a mathematical model to predict how far and how fast they would travel in a real cell under different conditions.
The team finds the cations are particularly mobile under more humid conditions, which are common in fuel cells, and thus make it more difficult to control the contaminants.
And they tended to get stuck within the thin catalyst layers, where they interfere with the reactions that produce electricity.
Learning more about how cation contaminants behave in a fuel cell should help scientists develop new materials and ways of running the cells that reduce contamination or help clear it away.
