A battery and an associated method are provided for generating power using an air cathode battery with a slurry anode. The method provides a battery with an air cathode separated from an anode current collector by an electrically insulating separator and an extrusion gap. The anode current collector extruder has a first plate with a plurality of slurry outlet perforations, and a sleeve having a first partition immediately adjacent to the extruder first plate, with a plurality of slurry inlet perforations. Active slurry is provided under pressure to an extruder inlet, and the extruder first plate slurry outlet perforations are selectively aligned with sleeve first partition slurry inlet perforations. Active slurry deposits are formed in the extrusion gap to mechanically charge the battery. In the discharge position, the sleeve moves so that the perforations no longer align, and slurry in the extruder is isolated from slurry in the extrusion gap.