Fuel cell system and fuel cells therefor

A fuel cell system comprising a plurality of fuel cells, each of said fuel cells including:

• an electrolyte layer in form of a plate;
• an oxygen electrode formed on one surface of said electrolyte layer;
• a fuel electrode formed on the other surface of said electrolyte layer;
• and
• gas passage defining means having conductivity and opposed to one of said oxygen electrode and said fuel electrode for defining oxygen-containing gas passages and fuel gas passages;
• wherein said gas passage defining means includes a plate portion opposed to and spaced from one of said oxygen electrode and said fuel electrode, a pair of strip-shaped projections extending along opposite ends of said plate portion for contacting opposite edges of said electrolyte layer, and a plurality of ridges for defining gas passages in form of grooves between said pair of strip-shaped projections;
• flexible conductive elements each disposed between an adjacent pair of said fuel cells, said fuel cells are stacked one over another in a spaced relationship to define fuel gas passages and oxygen-containing passages therebetween, each of said flexible conductive elements being a conductive separator;
• a first bar member and a second bar member having the same thickness as and longer than each of said cells being placed in contact with opposite side surfaces of each of said cells where said oxygen-containing gas passages and said fuel gas passages are closed by said conductive separator;
• a third bar member and a fourth bar member having the same thickness as and longer than each of said cells being placed in contact with opposite edges of each of said cells where said oxygen-containing gas passages and said fuel gas passages are open;
• and
• opposite ends of said first bar member and said second bar member being placed in contact with opposite ends of said third bar member and said fourth bar member, sets of the cell and bar members being stacked one over another in a spaced relationship to define fuel gas passages and oxygen-containing gas passages in between.