A rechargeable galvanic cell that has a negative electrode material made of a molten alkali metal (such as sodium or lithium). The galvanic cell also includes a positive electrode active material that may be sulfur or iodine. The positive electrode active material may be used in conjunction with a polar solvent. An ion-conductive separator is disposed between the polar solvent and the negative electrode material. The positive electrode active material has a specific gravity that is greater than the specific gravity of the polar solvent. Thus, the positive electrode active material is proximate the bottom of the positive electrode compartment while the polar solvent is above the positive electrode active material. The cell is designed to be operated at temperatures above the melting point of the alkali metal, but at temperatures that are lower than about 250° C.