Abstract: A metal-gas cell storage battery, such as a zinc-air cell battery, has one or more battery cells wherein each battery cell comprises a metallic anode sandwiched between a pair of gas cathodes. Each gas cathode is disposed within a rigid retaining structure. The retaining structures of each gas cathode are attached to one another by an expandable soft pocket capable of holding an electrolyte. The anode is disposed within the soft pocket. The cell is mechanically refueled by expanding the soft pocket to allow easy removal from the cell of the spent anode and easy insertion into the cell of a fresh anode.