Tubular solid oxide fuel cell assembly and fuel cell device incorporating same

A tubular solid oxide fuel cell assembly which comprises:

• a) at least two axially elongate tubular solid oxide fuel cell units sharing at least one external current collector, each fuel cell unit comprising:
• iii) first and second end sections and an intermediate section therebetween, and
• iv) an inner electrode layer, an outer electrode layer and an electrolyte layer therebetween;
• b) at least one external, shared current collector in electrical contact with an electrode layer of at least two fuel cell units, the current collector possessing a coefficient of thermal expansion greater than that of the fuel cell units, the current collector and each electrode layer in electrical contact therewith possessing substantially conforming electrical contact surfaces;
• and,
• c) at least one retainer configured to retain at least one section of at least two fuel cell units and at least a portion of shared current collector in close-fitting relationship therewith, the coefficient of thermal expansion of the retainer being less than or equal to that of the current collector, the portion of the current collector retained within the retainer when thermally expanded placing the electrode surface of each fuel cell unit in electrical contact therewith under compression.