Internal convection cell

An electrochemical cell comprising:

• a permeable fuel electrode configured to support a metal fuel thereon;
• an oxidant reduction electrode spaced from the fuel electrode;
• a second oxidant reduction electrode spaced from and opposing the oxidant reduction electrode, with the permeable fuel electrode being positioned between the oxidant reduction electrode and the second oxidant reduction electrode;
• an ionically conductive medium for conducting ions between the fuel and oxidant reduction electrodes to support electrochemical reactions at the fuel and oxidant reduction electrodes;
• a charging electrode selected from the group consisting of (a) the oxidant reduction electrode, (b) a separate charging electrode spaced from the permeable fuel electrode and the oxidant reduction electrode, and (c) a portion of the permeable fuel electrode;
• a gas bubble flow generator selected from the group consisting of (a) the charging electrode, and (b) a sparger spaced from the charging electrode, the gas bubble flow generator being configured to evolve gaseous oxygen bubbles that generate a flow of the ionically conductive medium during a charging operation;
• and
• one or more flow diverting surfaces configured to establish a circulation path that directs the flow of the ionically conductive medium at least partially through the permeable fuel electrode;
• wherein the one or more flow diverting surfaces establishes the circulation path as a closed circuit.

A method for flowing an ionically conductive medium in an electrochemical cell, the electrochemical cell comprising a permeable fuel electrode configured to support a metal fuel thereon, an oxidant reduction electrode spaced from the fuel electrode, a second oxidant reduction electrode spaced from and opposing the oxidant reduction electrode, with the permeable fuel electrode being positioned between the oxidant reduction electrode and the second oxidant reduction electrode, and a charging electrode selected from the group consisting of (a) the oxidant reduction electrode, (b) a separate charging electrode spaced from the fuel and oxidant reduction electrodes, and (c) a portion of the permeable fuel electrode, the fuel electrode, oxidant reduction electrode, and charging electrode each contacting the ionically conductive medium such that the ionically conductive medium may conduct ions therebetween, the oxidant reduction electrode being immersed in the ionically conductive medium with an air space associated therewith to provide a gaseous oxidant thereto, the method comprising:

• emitting gaseous bubbles in the ionically conductive medium that drag the ionically conductive medium upwards due to their buoyancy to generate a flow;
• wherein one or more flow diverting surfaces in the electrochemical cell establishes a circulation path that directs the flow of the ionically conductive medium upwardly and then laterally over a top of the oxidant reduction electrode and the air space, to a side thereof opposite the fuel electrode, and at least partially through the permeable fuel electrode.