put into other words,in accordance with the invention there is provided a method of making an alkali metal aluminum halide compound of the formula MAlHal4 as defined above,and alkali metal,which includes oprating an electrolytic cell which comprises said MAlHal4 in molten form separated from a molten alkali metal which is the same as the alkali metal in the MAlHal4,by a separator which is in contact with both said molten MAlHal4 and molten alkali metal and comprises a solid conductor of ions of said alkali metal or comprises a micromolecular sieve having said alkali metal sorbed therein,electrons from the external circuit of the electrolytic cell being fed into the molten alkali metal to give rise to reactions(1)and (2)as set out above.