A method for renovation of a consumed anode in a metal-air cell without dismantling the cell comprises circulating electrolyte through the cell to evacuate used slurry from the cell, circulating electrolyte with fresh slurry into the cell and allowing sedimentation of the fresh slurry inside the cell to form an anode and compacting the slurry to reduce the gaps between its particles. A meta-air cell enabling renovation of a consumed anode without dismantling the cell defining first outer face of the cell, air cathode layer adjacent the porous wall, separator wall disposed on the inner face of the air cathode layer, cell space volume to contain electrolyte and metal granules slurry, current collector layer to form an anode, made of current conductive material disposed in the space and flexible wall defining a second outer face of the cell wherein the flexible wall is adapted to be pushed towards inside of the cell subject to pressure applied to its outer face, thereby to reduce the volume of the space.