Patent ID: 7270907

Claim:
A liquid feed fuel cell system comprising: (A) a direct oxidation fuel cell including a membrane electrode assembly; (B) a source of liquid fuel; and (C) a fuel container coupled with said fuel cell, including: (i) a first inner bladder being substantially fully expanded upon being filled with liquid fuel, and having a fuel outlet conduit to suppply liquid fuel to said direct oxidation fuel cell; and (ii) a second inner bladder for receiving effluent from said fuel cell through an effluent inlet leading from said fuel cell into said fuel container, said second inner bladder being disposed directly contacting said first inner bladder such that as effluent is received from the fuel cell, the second inner bladder expands and contacts said first inner bladder displacing fuel from said first inner bladder to deliver fuel to said fuel cell, and wherein said second inner bladder is not under application of force.