Patent ID: 8709680
Filing Date: 2014-04-29
Classification: H01M,Y02E

Abstract:
1. A cell unit of a mixed reactant fuel cell, comprising (a) a porous electronically conductive distributor for flowing therethrough a multiphase mixed reactant fluid having fuel and oxidant each in separate fluid phases, wherein at least one of the fuel and oxidant fluid phases is a liquid; (b) an anode and a cathode each in fluid and electronic communication with the distributor, wherein the anode comprises a porous material having one or more properties that produce a selected capillary pressure when the reactant fluid contacts the anode, which causes a higher hold up of the fuel fluid phase than the oxidant fluid phase in the pores of the anode when the mixed reactant fluid flows through the distributor, thereby suppressing transfer of oxidant to the anode from the distributor, or wherein the cathode comprises a porous material having one or more properties that produce a selected capillary pressure when the reactant fluid contacts the cathode, which causes a higher hold up of the oxidant fluid phase than the fuel fluid phase in the pores of the cathode when the mixed reactant fluid flows through the distributor, thereby suppressing transfer of fuel to the cathode from the distributor; or both; and (c) a separator positioned relative to one of the anode and the cathode to provide electronic insulation and ionic communication between the cell unit and another adjacent cell unit; wherein the distributor extends between respective superficial surfaces of the anode and cathode of the cell unit such that the bulk mixed reactant fluid flows through the distributor and by the superficial electrode surfaces under conditions that produce a positive net potential of the fuel cell under load; and wherein the capillary pressures of the anode and cathode porous materials are a function of pore radii of the porous materials, the interfacial tension between the fuel and oxidant fluid phases, and properties of the porous materials which affect the contact angles of the fuel fluid phase relative to the oxidant fluid phase on the anode or cathode surfaces.