Sea water battery

This invention relates to sea water cells or salt water galvanic cells or batteries which use oxygen dissolved in the sea water as the oxidant, and in particular to cathodes which are suitable for cells which are exposed to high hydrodynamic forces (from waves or strong currents). The cathode (3, 12) may consist of a helix, or spirally wound perforated or expanded metal plate or sheet. The cathode (20) may alternatively consist of a number of concentrical spaced apart layers of cylinders of a perforated or expanded metal sheet. The number of layers of the cathode is 2-50. preferably 3-20. The layers of the cathode are spaced apart with radially arranged bars, spacers, notches (4, 15, 16) or the like.