NOVELTY - An ionic conducting membrane (1, 5, 6) is manufactured by polymerizing an aqueous solution of monomer(s) from water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent; and replacing a portion of the water of the aqueous solution with an alkaline solution, where the membrane is swelled to a thickness upon curing, prior to replacing a portion of water of the aqueous solution with the alkaline solution.    USE - The method is used for manufacture of ionic conducting membrane for supporting a liquid solution, for use in electrochemical devices, e.g. primary batteries, secondary batteries, and fuel cells such as metal/air (e.g. zinc/air, cadmium/air, lithium/air, magnesium/air, iron/air, and aluminum/air), zinc/nickel, zinc/manganese oxide, zinc/silver oxide, iron/nickel, lead-acid, nickel/cadmium, and hydrogen fuel cells; and electrochromic devices, e.g. smart windows and flat panel displays. It is useful as an electrolyte (7) source and as a dendrite resistant separator between the charging electrode and the anode, in secondary batteries (i.e. rechargeable). It is used in other electrochemical cell based devices, such as electrochemical cell gas separators and sensors. It is for use in liquid solutions of ionic species that are highly conductive to anions or cations. It is used in neutral systems, where solution supported by the invention comes from a solution including saturated aqueous neutral solution of ammonium chloride and potassium sulfate; a saturated solution of ammonium chloride, potassium sulfate, and sodium chloride; and a saturated neutral solution of potassium sulfate and ammonium chloride.    ADVANTAGE - The invention provides electrochromic device with the reliability and long lifetime associated with solution phase electrochromic systems, and the energy-saving memory properties associated with thin-film electrochromic systems. It provides a protective layer to the electrodes to prevent the usual sources of cell destruction. It prevents diffusion of zinc oxidation product into the electrolyte solution phase, prevents corrosion of the zinc anode by the electrolyte solution or air, and prevents blockage of the cathode (4) air channels by water from the electrolyte solution. It is easy to produce, much less expensive than existing proton conductive membranes, and functions well at room temperature.    DESCRIPTION OF DRAWING(S) - The figure is a schematic depiction of a zinc/air fuel cell incorporating an anode and a cathode protective polymer matrix membrane.    Ionic conducting membrane (1, 5, 6)    Cathode (4)    Electrolyte (7)