TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: The step of contacting the substrate surface to the acidic solution is conducted at 25-100degreesC for less than 600 seconds. The separating step involves rinsing the surface with a rinse solution to remove the acidic solution and the metal halide from the surface. The separating to remove the metal oxide reduces electrical resistance of the surface thus improving electrical conductivity of the element in the electrochemical cell. The amount of the metal oxides at the surface is lessened. The determining step includes evaluating thermodynamic phase data at conditions including pH, temperature, potential energy, and/or presence of halide anion(s).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The acidic solution comprises water, sulfuric acid, nitric acid, and/or preferably hydrofluoric acid. The metal oxide provides the source of the metal in the metal halide and the halogen ion provides the source of the halide in the metal halide species. The halogen ion is chlorine (Cl-), bromine (Br-), iodine (I-), and/or preferably fluorine (F-). Preferred Composition: The acidic solution having 2-4 comprises the halogen ions at a concentration of 1x10-3-1x10-5 molarity.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The acidic solution comprises water, sulfuric acid, nitric acid, and/or preferably hydrofluoric acid. The metal oxide provides the source of the metal in the metal halide and the halogen ion provides the source of the halide in the metal halide species. The halogen ion is chlorine (Cl-), bromine (Br-), iodine (I-), and/or preferably fluorine (F-). Preferred Composition: The acidic solution having 2-4 comprises the halogen ions at a concentration of 1x10-3-1x10-5 molarity. EXAMPLE - An electrically conductive element was prepared by providing stainless steel strips samples. A steel substrate was precleaned by spraying an alkaline cleaning solution of PARCO Clean 1200 (an alkaline cleaner with a builder constituent comprising potassium hydroxide and tetrapotassium pyrophosphate) at 5 weight % and 95 weight % deionized water for 10 seconds at 71degreesC. A deionized water rinse was sprayed onto the surface to remove any residual alkaline cleaning solution. An acidic treatment solution was prepared by mixing 3 weight % sulfuric acid solution; 97 weight % deionized water solvent; and 284 ppm of hydrogen fluoride. The acidic treatment solution was sprayed on the steel substrate surface for 10 seconds at 66degreesC to activate the surface and remove metal oxides. The steel substrate was sprayed for 10 seconds at 66degreesC with a first rinse solution comprising 1 weight % sulfuric acid and 99 weight % deionized water. The steel substrate was further sprayed for 10 seconds at 66degreesC with a second rinse solution comprising 100 weight % deionized water. The surface of the steel substrate was dried by a pair of squeegee rollers at 26degreesC, e.g. ethylene propylene rubber or polychloroprene. An electrically-conductive protective polymer coating matrix was applied to the stainless steel substrate by spray coating at room temperature. The stainless steel substrate having a spray coating of polymer matrix was placed in an oven at 150degreesC for 10 minutes to vaporize the solvents and placed in an oven at 260degreesC for 30 minutes to cure the polymeric matrix.