Abstract: There is disclosed a direct fuel cell comprising an anode and a cathode immersed in an electrolyte in the presence of a reductant and oxidant. Specifically, the fuel cell lacks a permselective membrane or other chemical barrier between the anode and cathode. Instead, the fuel cell has a mechanical/electrical porous separator that permits the free diffusion of liquid between all elements of the fuel cell. The fuel cell further contains an anode electrode of conductive substrate with catalyst and a cathode comprising a hydrophobic coated material that prevents cathode flooding. As a result, oxidation of the anode fuel and reduction of the cathode fuel occur to a substantial extent only at the anode and cathode, respectively, and is capable for ambient pressure/temperature and passive operation.