TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: The aqueous aluminum chloride solution is led into the water that is formed during the operation of the fuel cell.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metallic aluminum used has a degree of purity of 98-99.99%. The amount of aluminum in the aluminum alloy is about 0.01-1 g/kg and the metal is copper, iron, silicium, manganese, magnesium, nickel and/or zinc. The surface (where the aluminum and/or aluminum alloy is added) in the aqueous aluminum chloride solution is in tunnel structure exhibiting a diameter of less than 2 microns and preferably less than 100 nm. The aqueous aluminum chloride solution contains 1-400 (20-50) g/l of aluminum chloride. The aqueous aluminum chloride solution contains one or more corrosion inhibitors, preferably organic corrosion inhibitor such as carbonic acid, amine, alcohol as well as their derivatives containing groups and/or an inorganic corrosion inhibitor such as sulfuric acid, nitric acid and phosphoric acid containing groups. The aqueous aluminum chloride solution contains one or more corrosion activators, preferably at least one metal chloride and at least one chloride of a metal such as iron, copper, nickel or zinc. Preferred Process: The metallic aluminum and/or aluminum alloy is added to the aqueous aluminum chloride solution by chemical and/or electrochemical corrosion. In the process, inert gas is sprayed into the metallic aluminum and/or aluminum alloy for removing the residues in the enclosed air before adding into the aqueous aluminum chloride solution. The aqueous aluminum chloride solution exhibits about 10-100 (preferably 95-100)degreesC, during the dissolution of metallic aluminum and/or the aluminum alloy. The dissolution of metallic aluminum and/or aluminum alloy in the aqueous aluminum chloride solution is carried out in the presence of inert gas atmosphere (preferably nitrogen atmosphere). The ratio of aluminum as solid material to aqueous aluminum chloride solution is adjusted to about 100-5000 (preferably 500) m2 aluminum per m3 solvents. In the method, the aqueous aluminum chloride solution in cycle is led through a packing made of aluminum and/or aluminum alloy, gaseous reaction products are removed from the reaction chamber by introducing molecular nitrogen at an increased pressure and the polyaluminum chloride is removed continuously or discontinuously form the reaction mixture, where these steps are carried out continuously.