NOVELTY - An electrochemical cell (314) comprises an electrolyte; an anode (334) comprising metal particles and in a flowable suspension; a cathode (332) comprising a catalytic layer and a non-gaseous oxidizing agent having a reduction potential greater than the reduction potential of the metal particles in the anode, where the catalytic layer comprises a catalyst in a polymer binder; a separator; and a case comprising a channel.    USE - For stationary and mobile applications, e.g. electric vehicles.    ADVANTAGE - The electrochemical cell is efficient, environmentally safe and completely renewable. It offers zero emissions, lower maintenance costs, and higher specific energies resulting in weight reductions. It can give vehicle designers additional flexibility to distribute weight for optimizing vehicle dynamics.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a gas diffusion electrode for an electrochemical cell, comprising a porous backing layer, a catalytic layer comprising a matrix polymer and catalyst particles that catalyze the reduction of a gaseous oxidizing agent, and a compositionally distinct redox layer adjacent to the catalytic layer; and    (2) the production of current from an electrochemical cell comprising an anode and a cathode, comprising generating current through a closed circuit connecting the anode and the cathode by oxidizing metal particles at the anode and reducing an initial oxidizing agent at the cathode when a concentration of a gaseous oxidizing agent is not present in the cathode, and providing the gaseous oxidizing agent to the electrochemical cell so that when a concentration of the gaseous oxidizing agent is within the electrochemical cell, the electrochemical cell generates current by oxidizing the metal particles at the anode and reducing gaseous oxidizing agent at the cathode.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of a metal-air fuel cell designed for the continuous replenishment of metal fuel, in which a sectional side view of an anode is shown in phantom lines.    Zinc-air fuel system (300)    Zinc fuel tank (302)    Electrochemical cell (314)    Cathode (332)    Anode (334)