NOVELTY - Redox fuel cell comprises: an anode and an cathode separated by a porous nonconductive separator; means to supply a fuel to the anode region of the cell; means to supply an oxidant to the cathode region of the cell; means to provide an electrical circuit between the anode and the cathode; and a non-volatile catholyte solution in fluid communication with the cathode. The catholyte solution comprises a redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by reaction with the oxidant after such reaction at the cathode.    USE - The redox fuel cell is useful as a proton exchange mechanism fuel cell to produce electricity (all claimed) in electronic and portable electronic environments, and as larger fuel cells for the automotive industry and for stationary applications.    ADVANTAGE - The redox fuel cell has enhanced safety and convenience, and utilizes a porous separator rather than a membrane, hence higher temperatures can be used and thus the fuel cell has an enhanced operating range and enhanced proton conductivity can occur at higher temperatures.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a redox fuel cell comprising an anode and a cathode assembly, separated by a nonconductive porous separator, means for supplying a fuel to the anode assembly, means for supplying an oxidant to the cathode assembly, means for providing an electrical circuit between respective anodes and cathodes of the cell and a catholyte solution comprising at least one catholyte component, where the catholyte solution comprises a redox mediator couple, the cathode assembly comprises a catholyte inlet channel and at least one flow channel in fluid communication with the catholyte inlet channel, the flow channels are defined by flow channel walls comprising at least one porous cathode regions, at least one of the flow channels is non-aligned with the catholyte inlet channel, at least one of the flow channels is dosed at one end, and the cathode region is provided along substantially the entirety of the walls defining the flow channels;    (2) a redox fuel cell comprising many stacks of electrode assemblies, where each electrode assembly comprises an anode and a cathode separated by a porous nonconductive separator, an anode chamber adjacent the anode of each electrode assembly, a cathode chamber adjacent the cathode of each electrode assembly, means for supplying a fuel to the anode chambers of the cell, means for supplying an oxidant to the cell, means for providing an electrical circuit between respective anodes and cathodes of the cell, a catholyte solution comprising at least one non-volatile catholyte component, where the catholyte solution comprises a redox mediator couple, and a regeneration zone separated from the electrode assemblies, where the means for supplying an oxidant to the cell is adapted to supply the oxidant to the regeneration zone;    (3) a redox fuel cell comprising many stacks of electrode assemblies, where each electrode assembly comprises an anode and a cathode separated by a porous nonconductive separator and each electrode assembly comprises an anode chamber adjacent the anode of that assembly and a cathode chamber adjacent the cathode of that assembly, means for supplying a fuel to the anode chambers of the cell, means for supplying an oxidant to the cell, means for providing an electrical circuit between respective anodes and cathodes of the cell, a catholyte solution comprising at least one non-volatile catholyte component, where the catholyte solution comprises a redox mediator couple, optionally, means upstream and/or downstream of the cathode chambers for cooling the catholyte solution, and a regeneration zone separated from the electrode assemblies, where the means for supplying an oxidant to the cell is adapted to supply the oxidant to the regeneration zone, the regeneration zone is maintained in operation of the cell at an operating temperature at least 2 degrees C higher than the cathode chambers of the cell and/or at a higher operating temperature than that of the cooling means;    (4) a redox proton-exchange-mechanism fuel cell comprising a porous nonconductive separator; and    (5) operating a proton-exchange-mechanism fuel cell comprising forming hydrogen ions (H+) at an anode situated adjacent to a porous nonconductive separator, supplying the catholyte with its redox couple in an oxidized state to a cathode situated oppositely adjacent to the porous separator and allowing the catalyst to become reduced upon contact with the cathode concomitantly with hydrogen ions passing through the porous separator to balance charge.