Patent ID: 8785070
Filing Date: 2014-07-22
Classification: H01M,Y02E,Y10S

Abstract:
1. A method of operating a direct oxidation fuel cell (DOFC) system, wherein the system comprises: (i) at least one membrane electrode assembly which includes a cathode, an anode and an electrolyte positioned therebetween, said cathode comprises, in direct overlying sequence, a catalyst layer, a microporous layer and a gas diffusion medium (GDM), wherein said microporous layer comprises an electrically conductive material and a fluoropolymer which is in a range about 10 wt. % to about 60 wt. %, wherein said microporous layer has a thickness ranging from about 10 to about 50 μm and an average pore size between about 10 and about 500 nm, and said GDM comprises a backing layer, and (ii) a liquid/gas separator, the method comprising: supplying a concentrated solution of a liquid fuel to said anode and an oxidant to said cathode which produces water, wherein some of the produced water is transported to the liquid/gas separator and subsequently supplied to the anode; and operating said at least one membrane electrode assembly at a low oxidant stoichiometry ξc not greater than about 4; wherein  and ξ