Electrochemical reduction of CO2 is viewed as one of the most attractive ways to store renewable energy because CO2 can be reduced to a number of gaseous (CO) or liquid fuel products (formic acid, methanol, and hydrocarbons), the technology of which is well developed. Additional impetus to this topic is given by the growing necessity to limit the amount of CO2 emitted into the atmosphere.
Electrolysis of molten Li2CO3 at 900°C with a Ti cathode and a graphite anode is a feasible method for electrochemical reduction of CO2 to CO. In this method electrolysis causes decomposition of Li2CO3 to Li2O (dissolves in Li2CO3), CO and O2. Supplied CO2 converts Li2O back to Li2CO3. During a test period of hundreds of hours, the Faradaic efficiency of the process at 900oC is close to 100% and the thermodynamic efficiency at 0.1 A/cm2 is at least 85%.
Industrial scale prototype ( 150-200 kg Li2CO3) was designed and built:
Kaplan V, Wachtel E, Lubomirsky I, Titanium Carbide Coating of Titanium by Cathodic Deposition from a Carbonate Melt. Journal of The Electrochemical Society, 159 (11) E159-E161 (2012)
Kaplan V, Wachtel E, Lubomirsky I, Conditions of stability for (Li2CO3 + Li2O) melts in air. J. Chem. Thermodynamics 43 (2011) 1623–1627
Kaplan V, Wachtel E, Gartsman K, Feldman Y, Lubomirsky I, (2010) Conversion of CO2 to CO by Electrolysis of Molten Lithium Carbonate. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 157:B552-B556.