Fuel cell chip enables scaling for clean energy applications

While SOFCs have previously worked at the micro scale, the researchers believe this is the first time anyone has overcome the structural challenges of scaling up the technology to a practical size with a proportionally higher power output. "The breakthrough in this work is that we have demonstrated power density comparable to what you can get with tiny membranes, but with membranes that are a factor of a hundred or so larger - meaning the technology is scalable," said principal investigator Shriram Ramanathan, associate professor of materials science at SEAS. "The development indicates the potential of electrochemical fuel cells to be a viable source of clean energy." Together with researchers from SiEnergy Systems LLC, Prof Ramanathan and his team fortified thin film membranes using a metallic grid that looked like nanoscale chicken wire. The tiny metal honeycomb provided the critical structural element for the large membrane, while also serving as a current collector. The team was then able to manufacture membrane chips that were 5mm wide, combining hundreds of these chips into palm sized SOFC wafers. According to the Professor, the fuel cells had a power density of 155 milliwatts per square centimetre (at 510°C), comparable to the power density of micro SOFCs. When multiplied by the much larger active area of this new fuel cell, that power density translated into an output high enough for relevance to portable power. The researchers hope that future work on SOFCs will incorporate these technologies into the large scale fuel cells, improving their affordability. They now plan to explore the design of novel nanostructured anodes for hydrogen alternative fuels that are operable at these low temperatures and work to enhance the microstructural stability of the electrodes. The research was supported in part by the National Science Foundation and has been published in the 3 April edition of the journal Nature Nanotechnology.