TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The battery is a primary or a secondary battery. The secondary battery maintains a discharge capacity of at least 50% of an initial discharge capacity after 50 discharge cycles. The cathode material comprises spinel-dimanganese(III) tetraoxide or vanadium pentoxide (both preferred), titanium di(tetrachloroaluminate), manganese chloride tetrachloroaluminate or cobalt di(tetrachloroaluminate). The electrolyte comprises an ionic liquid. The electrolyte further comprises aluminum chloride, and the ratio of aluminum chloride to the aluminate is greater than 1:1. The electrolyte further comprises an alkali metal halide additive. The electrolyte comprises ethylmethylimidazolium tetrachloroaluminate and aluminum chloride. The molar ratio of aluminum chloride to ethylmethylimidazolium tetrachloroaluminate is greater than 1:1. The electrolyte comprises an organic solving having a high dielectric constant. The battery comprises: an aluminum metal anode; a gamma -manganese oxide cathode capable of intercalating aluminum ions during a discharge cycle and deintercalating the aluminum ions during a charge cycle; and an ionic liquid electrolyte comprising aluminum chloride and ethylmethylimidazolium tetrachloroaluminate, having a molar ratio of aluminum chloride to ethylmethylimidazolium tetrachloroaluminate of greater than 1:1, where the electrolyte is capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum at the cathode.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The ionic liquid is an aluminate comprising alkylimidazolium aluminates, alkylpyridinium aluminates, alkylfluoropyrazolium aluminates, alkyltriazolium aluminates, aralkylammonium aluminates, alkylalkoxyammonium aluminates, aralkylphosphonium aluminates and/or aralkylsulfonium aluminates. The alkali metal halide additive is sodium chloride, potassium chloride and/or ammonium chloride. The ionic liquid is a neutral ionic liquid comprising: a cation comprising a piperidinium cation of formula (a), a pyrrolidinium cation of formula (b), a 3H-imidazol-1-ium cation of formula (c) or quaternary ammonium cation of formula ((R1)(R2)(R3)(R4)N+) (d); and an anion comprising trifluoromethanesulfonate, boron tetracarbonate (B(CO2)4), bis(perfluoroethylsulfonyl)imide, bis(trifluoromethanesulfonyl)imide, bis( fluorosulfonyl)imide, hexafluorophosphate, tetrafluorborate or fluoroborate anion of formula (BF4-x(CnF2n+1)x-). The organic solvent is propylene carbonate, ethylmethylsulfone, ethylmethoxyethylsulfone or methoxyethylmethylsulfone.R1-R4 = non-ionizable substitutent;x = 1-3; andn = 1-10.