Electrochemical cells and methods are described that can be utilized for the recovery of tritium directly from a molten lithium metal solution without the need for a separation or concentration step prior to the electrolytic recovery process. The methods and systems utilize an ion conducting electrolyte that conducts either lithium ion or tritide ion across the electrochemical cell.

Methods separates a gas comprising providing a first electrode in ion-conducting contact with an electrolyte, providing a second electrode in ion-conducting contact with the electrolyte, wherein the second electrode comprises a liquid metal, providing a displacing material comprising a first surface in contact with the second electrode and a second surface exposed to an environment outside the second electrode, wherein said material permits flow of gas and impedes flow of liquid metal, and establishing a potential between the first and second electrodes, whereby gas flows toward the liquid metal. Other aspects include methods and apparatuses comprising electrodes, electrolytes and displacing materials.