Patent ID: 7955739

Claim:
A fuel cell stack comprising: first and second end plates, the second end plate having a heat rejection surface; a plurality of fuel cells interposed between the first and second end plates and including an end cell associated with the first end plate, each fuel cell having a membrane electrode assembly having a cathode side and an anode side interposed between anode and cathode flow fields, respectively; a thermal mass interposed between the first end plate and the end cell and in thermal communication with the end cell; a first insulating layer interposed between the first end plate and the thermal mass; and a second insulating layer surrounding the plurality of fuel cells, wherein the size of the thermal mass and the sizes of the first and second insulation layers are selected such that water is passively transferred from the membrane electrode assemblies to one of the anode and cathode flow fields in each of the plurality of fuel cells during shutdown of the fuel cell stack, and wherein the thermal mass acts as a heat reservoir that establishes a decreasing temperature profile across the stack during shutdown of the fuel cell stack.