We developed new electrolytes for aluminum deposition based on AlCl 3 /dialkylsulfones (XSO 2 ) mixtures usable in the 40-150°C temperatures range along the melting point of the sulfone choosen. NMR study of these electrolytes showed that they contain AlCl - 4 , Al(XSO 2 ) 3 + 3 and 1 : 1 molecular adducts AlCl 3 -XSO 2 ; this latter Al species is formed at the expense of Al(XSO 2 ) 3 + 3 , especially in diethylsulfone and dipropylsulfone-based electrolytes. The Al species responsible for aluminum deposition has been shown to be Al(XSO 2 ) 3 + 3 . Al deposits formed from AlCl 3 /XSO 2 electrolytes exhibit fine grain size, relatively smooth surface aspect and high purity. High deposition rates (> 50 μm h - 1 ) and thick Al deposits with thickness up to a few hundreds micrometers were obtained from AlCl 3 /dimethylsulfone at 130°C.