Rechargeable hybrid sodium metal-sulfur battery

A rechargeable galvanic cell comprising:

• a negative electrode compartment housing a negative electrode active material, wherein
• the negative electrode active material comprises a liquid alkali metal wherein the alkali metal is selected from the group consisting of sodium and sodium alloys, and
• the negative electrode compartment is in fluid communication with a first reservoir such that the liquid alkali metal may passively flow between the negative electrode compartment and the first reservoir as the galvanic cell charges or discharges;
• a positive electrode compartment housing a mixture of a positive electrode active material and a positive electrolyte, wherein
• the positive electrode active material comprises elemental sulfur and/or Na2Sx depending on the charge state of the galvanic cell, wherein x has a value between 1 and 32,
• the positive electrolyte comprises a polar organic solvent, optionally comprising a polar protic organic solvent, that partially or completely dissolves the Na2Sx, and
• the positive electrode compartment is in fluid communication with a pump and a second reservoir such that the pump may circulate the positive electrode active material and positive electrolyte between the second reservoir and the positive electrode compartment during charge or discharge of the galvanic cell;
• and
• a sodium ion conductive ceramic membrane separating the negative electrode compartment from the positive electrode compartment.