TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Cell: The electrochemical cell comprises an anode compartment positioned between an anode side of the polymer electrolyte membrane and the housing. The electrochemical cell further comprises an inlet port in fluid communication with the anode compartment and configured to allow water flow into the anode compartment. The electrochemical cell further comprises cathode-polymer electrolyte membrane structures positioned within the housing. When the cathode is porous, and comprises a cathode tube, then the electrochemical cell further includes a cathode compartment including an interior space of the cathode tube. When the cathode is non-porous, then the electrochemical cell further comprises a cathode compartment located between the cathode and the polymer electrolyte membrane. Preferred Components: The cathode and the polymer electrolyte membrane surrounding the cathode comprise rod-shaped cathode-electrolyte membrane structures arranged in a radial configuration. The polymer electrolyte membrane comprises a first seal on a first end and a second seal on a second end. The housing is configured to contain an electrolyte, where the electrolyte comprises hydroxide ions. In the system (s1), the electrochemical cell further comprises an electrolyte circulation system configured to introduce, circulate and/or flush electrolyte solution from the electrochemical cell. In the method (m1), the cathode and the polymer electrolyte membrane surrounding the cathode comprises rod-shaped cathode-electrolyte membrane structures arranged in a radial configuration, where the hydrogen gas is collected at a pressure of 30-60, 200-500 or 1000-3000 psig, where the polymer electrolyte membrane comprises a first seal on a first end and a second seal on a second end.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrolyte further comprises aqueous halide salt.    TECHNOLOGY FOCUS - METALLURGY - Preferred Components: The cathode comprises a first metal selected from nickel and nickel alloys of Pt, Pd, Cr, Mo, Fe, Ta, Ru, Rh, W, Os, Ir, Zn, Co, Ti or Zr. The anode comprises a second metal selected from austenitic stainless steels, duplex stainless steels, nickel and nickel alloys of Pt, Pd, Cr, Mo, Fe, Ta, Ru, Rh, W, Os, Ir, Zn, Co, Ti or Zr.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymer electrolyte membrane is selected from a perfluorinated ionomer and a copolymer of ethylene and a vinyl monomer containing an acid group or its salt. The perfluorinated ionomer is selected from perfluorosulfonic acid/tetrafluoroethylene copolymers and perfluorocarboxylic acid/tetrafluoroethylene copolymer. The polymer electrolyte membrane comprises an anionic exchange membrane. EXAMPLE - No suitable example given.