A fuel cell including a water blocking layer positioned between anode gas
flow channels and a gas diffusion media. The blocking layer prevents
water from propagating through the gas diffusion media layer and entering
the anode flow channels, while allowing gas from the flow channels to
flow through the diffusion media layer to the membrane. A water
accumulation channel can be provided around the perimeter of the gas
diffusion media layer where blocked water is accumulated, and allowed to
expand during cell freezing. A porous capillary wick can be provided in
the accumulation channel for wicking water to the inlet end of the flow
channels where it is used to humidify the anode gas coming into the fuel
cell. The wick can have a tapered configuration so that it has a larger
diameter at the gas input end of the flow channels.