This fuel cell technology is a thin composite membrane of c-axis aligned hydroxyapatite single crystals to optimize proton transport grown on a palladium alloy membrane base. Applications: This membrane is intended to enable a new class of fuel cells to operate in the temperature range of 200-600oC. It may also be useful in gas sensors and electro-catalytic devices.
1) The temperature range of 200-600oC would be low enough for construction of fuel cells using low cost materials but be high enough to enable the use of non-precious metal catalysts and to allow internal fuel reforming of hydrocarbon fuels. 2) This membrane can enable a new class of fuel cells intermediate to those which use polymeric electrolyte membrane which must operated below 100oC and solid oxide fuel cells with ceramic membranes which operate most effectively above 700oC. 3) Fabrication is by electrochemical deposition which can coat large areas at low cost and could be applicable to both tubular and planar construction.