New material with colossal ionic conductivity could lead to more efficient fuel cellsAugust 2nd, 2008 - 2:20 pm ICT by ANI
Washington, August 2 (ANI): Scientists have developed a new material that improves ionic conductivity near room temperature by a factor of almost 100 million, representing a colossal increase in ionic conduction properties, which could open a pathway toward more efficient fuel cells.
The material, a super-lattice developed by researchers in Spain, was characterized at the Department of Energys Oak Ridge National Laboratory (ORNL) in the US.
The analysis was done with ORNLs 300 kilovolt Z-contrast scanning transmission electron microscope, which can achieve aberration-corrected resolutions near 0.6 angstrom, until recently a world record.
The direct images show the crystal structure that accounts for the materials conductivity.
According to Maria Varela of ORNLs Materials Science and Technology Division, It is amazing. We can see the strained, yet still ordered, interface structure that opens up a wide pathway for ions to be conducted.
Solid oxide fuel cell technology requires ion-conducting materials - solid electrolytes - that allow oxygen ions to travel from cathode to anode.
However, existing materials have not provided atom-scale voids large enough to easily accommodate the path of a conducted ion, which is much bigger than, for example, an electron.
The new layered material solves this problem by combining two materials with very different crystal structures. The mismatch triggers a distortion of the atomic arrangement at their interface and creates a pathway through which ions can easily travel, said Varela.
Other fuel cell materials force ions to travel through tight pathways with few spaces for the ions to occupy, slowing their progress.
Rather than forcing the ions to jump from hole to hole, the new material has lots of vacant spaces to be occupied, so the ions can travel much more quickly, said Varela.
Unlike previous fuel cell materials, which have to achieve high temperatures to conduct ions, the new material maintains ionic conductivity near room temperatures. (ANI)
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