Georgia Tech researchers have developed a new ceramic material that could help expand the applications for solid oxide fuel cells – devices that generate electricity directly from a wide range of liquid or gaseous fuels without the need to separate hydrogen.
Though the long-term durability of the mixed ion conductor material still needs to be proven, its development could address two problems facing the solid oxide fuel cells: tolerance of sulfur in fuels, and resistance to carbon build-up known as coking. The new material could also allow solid oxide fuel cells – which convert fuel to electricity more efficiently than other fuel cells – to operate at lower temperatures, potentially reducing material and fabrication costs.
“The development of this material suggests that we could have a much less expensive solid oxide fuel cell, and that it could be more compact, which would increase the range of potential applications,” said Meilin Liu, a Regent’s professor in the School of Materials Science and Engineering. “This new material would potentially allow the fuel cells to run with dirty hydrocarbon fuels without the need to clean them and supply water.”
Like all fuel cells, solid oxide fuel cells (SOFCs) use an electrochemical process to produce electricity by oxidizing a fuel. SOFCs use a ceramic electrolyte known as yttria-stabilized zirconia (YSZ). The fuel cell’s anode uses a composite consisting of YSZ and nickel. This anode provides excellent catalytic activity for fuel oxidation, good conductivity for collecting current generated, and compatibility with the cell’s electrolyte – which is also YSZ.