US Patent 7435492 Hybrid fuel cell

A hybrid fuel cell/battery including one or more electrochemical cell units comprising at least one cathode, at least one anode, and at least one auxiliary electrode. The auxiliary electrode works in combination with the anode to provide a current as a rechargeable battery while the anode and cathode work in combination to provide an electrical current as a fuel cell. The cathode and the auxiliary electrode may operate alone or in tandem to provide an electrical current.