A non-porous Zn 2+ conducting inorganic lamellar layer is formed on the zinc coating of galvanized steel or on a zinc anode of an electrochemical cell. The layer reduces the rate of the unwanted chemical reaction of zinc and oxygen but allows desired electrochemical reactions underlying the cathodic protection of the steel and the efficient utilization of zinc anodes in electrochemical cells, e.g., a physiological buffer solution or serum as their electrolytes. The ion conducting non-porous lamellar layer having a hopeite phase Zn 3 (PO 4 ) 2 .4H 2 O may be formed spontaneously on, e.g., NAFION® coated zinc anodes discharged in neutral pH saline phosphate solutions.