Electrochemical cell system with a progressive oxygen evolving electrode / fuel electrode

A method for charging an electrochemical cell, wherein the electrochemical cell comprises:

• (i) a fuel electrode comprising N permeable electrode bodies arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies;
• (ii) an oxidant electrode spaced apart from the fuel electrode;
• (iii) a charging electrode selected from the group consisting of (a) the oxidant electrode, and (b) a separate charging electrode spaced from the fuel and oxidant electrodes;
• and
• (iv) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;
• wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;
• the method comprising:
• applying a cathodic potential to electrode body 1 by coupling electrode body 1 to a power source;
• managing application of an anodic potential to electrode bodies 2 to N by selectively coupling electrode bodies 2 to N to the power source for application of the anodic potential, so as to cause
• (a) electrodeposition of the metal fuel, via reduction of reducible ions of the metal fuel from the ionically conductive medium, to grow progressively from electrode body 1 towards the charging electrode with the electrodeposition progressively connecting each subsequent electrode body 2 to N to the electrode body 1 for application of the cathodic potential to each subsequently connected electrode body,
• (b) removal of the anodic potential from each subsequently connected electrode body, and
• (c) application of the anodic potential to at least the subsequent electrode body unconnected by the electrodeposition, or the charging electrode where electrode body N has been connected by the electrodeposition, for oxidation of an oxidizable species of the oxidant;
• and
• decoupling the power source to discontinue the charging.

An electrochemical cell system for generating electrical current using a metal fuel and an oxidant, the cell system comprising:

• an electrochemical cell comprising:
• (i) a fuel electrode comprising N permeable electrode bodies arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies;
• (ii) an oxidant electrode spaced apart from the fuel electrode;
• and
• (iii) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;
• wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;
• a plurality of switches for selectively coupling each electrode body 2 to N of the fuel electrode to the load;
• one or more sensors associated with the electrode bodies 2 to N, configured to determine the presence of consumable fuel on each electrode body 2 to N;
• and
• a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the electrode bodies 2 to N which the one or more sensors detect has the fuel depleted therefrom.

A method for discharging an electrochemical cell system, wherein the electrochemical cell system comprises:

• an electrochemical cell comprising:
• (i) a fuel electrode comprising a plurality of permeable electrode bodies arranged in spaced apart relation, the fuel electrode comprising metal fuel on the permeable electrode bodies;
• (ii) an oxidant electrode spaced apart from the fuel electrode;
• and
• (iii) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;
• wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;
• a plurality of switches for selectively coupling each electrode body of the fuel electrode to the load;
• one or more sensors associated with the permeable electrode bodies, configured to determine the presence of consumable fuel on each of the permeable electrode bodies;
• and
• a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the permeable electrode bodies which the one or more sensors detect has fuel depleted therefrom;
• the method comprising:
• discharging the electrochemical cell as connected to the load, so as to consume metal fuel from the permeable electrode bodies;
• sensing, with the one or more sensors, depletion of the metal fuel from the one or more of the permeable electrode bodies;
• disconnecting from the load, using the plurality of switches, each of the one or more of the permeable electrode bodies depleted of metal fuel;
• and
• continuing said discharging, sensing, and disconnecting until all metal fuel is depleted from the fuel electrode, or no further discharging is desired.