TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The metal ligand coordination compound (B) contains aluminum, calcium, cobalt, chromium, iron, magnesium, titanium, vanadium, zinc and/or zirconium. The mobile ion contains lithium ion, potassium ion, sodium ion, divalent magnesium ion, divalent calcium ion, divalent strontium ion and boron ion. The reinforcement material contains nylon, cotton, polyesters, crystalline silica, crystalline titania, amorphous silica, amorphous titania, rubber and/or asbestos wood. The membrane further contains reinforcement material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The ligand contains cyanide, water, halo, hydroxyl, amine, polyamine, polyalcohol, anions of carboxylic acid, dicarboxylic acid, polycarboxylic acid, amino acid, carbonyl or carbon monoxide carbonyl or carbon monoxide, nitride, oxo, sulfide, pyridine, pyrazine, amido group, imido group, alkoxy group, siloxy, thiolate, catechol, bipyridine, bipyrazine, ethylenediamine, diols, terpyridine, diethylenetriamine, triazacyclononane, trisaminomethane, quinone, hydroquinone, viologen, pyridinium, acridinium and polycyclic aromatic hydrocarbon. The separator is a porous membrane having pores with average size distribution of 0.001-100 nm. At least one layer of flow battery contains electrolyte (A) or (B) to be imbibed onto the separator.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The polymer is chosen from polytetrafluoroethylene, polyvinyl, polystyrene, polyethylene, polypropylene, polyesters, perfluoriniated polymers, polyvinylidene fluoride, poly(vinyl chloride), substituted vinyl polymers and polystyrene. At least one layer of flow battery which is capable of selective ion transport comprises perfluorinated sulfonate polymer, perfluoriniated hydrocarbon sulfonate ionomers, sulfonated polyetherether ketone, sulfonated poly(phthalazinone ether ketone), sulfonated phenolphthalein poly(ether sulfone), sulfonated polyimides, sulfonated polyphosphazene, sulfonated polybenzimidazole, and/or polyaromatic ethers with sulfonic or carboxylic acid groups.