Patent ID: 7618735
Filing Date: 2009-11-17
Classification: H01M,Y02E

Abstract:
1. A fuel cell formed by stacking an electrolyte electrode assembly and separators alternately, said electrolyte electrode assembly including a pair of electrodes and an electrolyte interposed between said electrodes, wherein a reactant gas supply passage and a reactant gas discharge passage extend through said fuel cell in a stacking direction of said fuel cell; a reactant gas flow field is formed for supplying a reactant gas along an electrode surface; said reactant gas flow field includes a plurality of serpentine flow grooves having substantially the same length, said serpentine flow grooves including an even number of turn regions formed on a surface of said separator; a substantially triangular inlet buffer for connecting said serpentine flow grooves and said reactant gas supply passage; a substantially triangular outlet buffer for connecting said serpentine flow grooves and said reactant gas discharge passage; wherein the reactant gas supply passage and the reactant gas discharge passage are positioned on extensions of the respective terminal portions of the serpentine flow grooves, each of the inlet buffer and the outlet buffer has a first side that forms an interface with terminal portions of the serpentine flow grooves, the first side of each of said inlet buffer and said outlet buffer is substantially perpendicular to the terminal portions of said serpentine flow grooves; each of the inlet buffer and the outlet buffer has a second side that is substantially parallel to the terminal portions of said serpentine flow grooves; each of the inlet buffer and the outlet buffer has a third side that is oblique to the first and second sides of each of the inlet buffer and the outlet buffer, the third oblique side of each of the inlet buffer and the outlet buffer is substantially parallel to one side of each of the reactant gas supply passage and the reactant gas discharge passage; and said inlet buffer and said outlet buffer are formed substantially symmetrically with each other.