A little strain goes a long way in reducing fuel cell performance

Science Daily  September 9, 2022
Using a proton-conducting oxide as an electrolyte film in electrochemical devices introduces an interface, which thermally and chemically generates mechanical strain. To reduce the strain researchers in Japan focused on BZY20, which is a combination of yttrium, barium, zirconium, and oxygen atoms. They found that the atoms on the edges of this cube are 2% closer at the interface between the oxide and the surface than in layers far away from the surface. This compressive strain reduces the proton conductivity to nearly 1/100,000 of what it is in bulk samples. As the layers build up, this compressive strain slowly reduces, with the cube eventually reaching its preferred size far from the interface. But while conductivity may be high away from the surface, the damage is already done. They showed that a 2% reduction in the distance between atoms when deposited on a surface leads to a 99.999% decrease in the speed at which the materials conduct hydrogen ions, greatly reducing the performance of solid oxide fuel cells. According to the researchers developing methods to reduce the strain will help bring high-performance fuel cells for clean energy production to a wider number of households in the future…read more. Open Access TECHNICAL ARTICLE