PORTLAND, Ore.—Fuel cells on-a-chip could replace small batteries, according to Harvard University researchers who showed a wafer containing 145 solid-oxide fuel cells.
The research team, led by professor and principal investigator Shriram Ramanathan, had previously proven the concept of fabricating thin-film membranes for solid-oxide fuel cells, but only at sizes too small to replace small batteries. Now the team, in collaboration with SiEnergy Systems LLC (an Allied Minds company in Boston), has demonstrated that the technology can successfully be scaled up.
The team fabricated the tiny fuel-cells with 100-nanometer thick membranes on chips that scaled up their area from 100 microns to 5 millimeters wide, achieving a power density of 155 milliwatts per square centimeter (at 510 degrees Celsius).
Next the team plans to fabricate nanostructured anodes for hydrogen-alternative fuels and microstructured electrodes, which together should enable the tiny fuel cells to replace small batteries.
Funding for the project was provided by the National Science Foundation (NSF) and the Harvard University Center for Nanoscale Systems, which is a member of the NSF's National Nanotechnology Infrastructure Network.
Harvard was able to pack 145 thin-film fuel cell batteries on a single wafer.