Carbon dioxide was electrochemically decomposed to carbon and oxygen gas in molten LiCl-5.0 wt.% Li2O molten salts at 903 K using a titanium cathode and inert platinum anode. CO2 chemically dissolves into the LiCI-Li2O melt by reacting with Li2O, changing the electrolyte LiCI-Li2O-O-2 into Li2CO3 and LiCI. Carbonate anions are electrochemically reduced to carbon on the cathode, while oxygen complexes of carbonate anions are oxidized at the anode, generating O-2. Electrolysis of the LiCI-5.0 wt.% Li2O molten salt under a CO2 atmosphere at 0.05 A/cm(2) yields anodic gas with a CO2/O-2 ratio of 0.42. The CO2/O-2 ratio increases with increasing current density. The proposed concept may provide oxygen and fuel supplies to future explorers and inhabitants of Mars. (C) 2015 Elsevier Ltd. All rights reserved.