Electrochemical metal-air cell and electrically and mechanically rechargeable anodes for use therein

An electrochemical metal-air cell, for multiple discharge and recharge cycles, comprising:

• (a) a housing having a base, two major surfaces and two minor surfaces defining an interior space for containing therein a replaceable metal electrode having a generally planar electrically conductive skeletal member encompassed by an active metal component, said interior space communicating with an opening opposite said base through which said replaceable metal electrode is selectively removed to enable the mechanical replacement thereof with a freshly charged metal electrode;
• (b) at least one generally planar air permeable but liquid impermeable air electrode, each of said at least one air electrode installed in a window opening provided in at least one of said major surfaces;
• (c) an electrolyte in contract with the metal and air electrodes;
• and further comprising
• (d) one or more auxiliary electrodes positioned in a spaced-apart relationship with and adjacent to said replaceable metal electrode;
• each auxiliary electrode constituting a charging anode which upon application of electrical current thereto is engaged via said electrolyte in a charging circuit with said metal electrode for effecting electrical recharging of said metal electrode by the reduction and regeneration of said active metal component of said metal electrode in an electrical charging mode of operation, during which said air electrode is disengaged with said metal electrode forming an open circuit between said air electrode and said metal electrode;
• and each of said auxiliary electrodes is disengaged from said metal electrode while said air electrode is engaged therewith in a discharging mode of operation, whereby said metal electrode is periodically, selectively removed from said interior space via said opening to enable the mechanical replacement thereof and is periodically, selectively electrically recharged in situ by the application of electric current to said auxiliary charging anode to reduce oxidized active metal of said metal electrode.