An electrochemical fuel cell includes an electrolyte membrane, a first
electrode on one side of the electrolyte membrane and a second electrode
on another side of the electrolyte membrane, a first separator and a
second separator, and a seal. The first and second separators sandwich the
first and second electrodes. The seal is provided between the electrolyte
membrane and one of the first and second separators for sealing a path of
a fuel gas or an oxidative gas, and between the first and second
separators for sealing a coolant path. The softer layer in the seal
elastically deforms and absorbs a surface roughness of the electrolyte
membrane or the electrode. The harder layer supports the electrolyte
membrane or the electrode. The seal can respond to and follow a length of
the electrolyte membrane or the separator changed by varying temperature.
