Carbon electrode with perovskite-oxide catalyst for aqueous electrolyte lithium-air secondary batteries

Carbon electrodes with perovskite-type oxide catalysts were investigated as air electrodes for aqueous lithium-air secondary batteries. The system consisted of a water-stable lithium electrode, an aqueous solution of saturated LiOH with 10 M LiCl as electrolyte, and a carbon black air electrode with perovskite catalyst additive. The stability, oxygen reduction and oxygen evolution catalytic activity of the La0.6Ca0.4Co0.8Fe0.2O3, La0.8Sr0.2Fe0.8Mn0.2O3, and La0.6Sr0.4Co0.2Fe0.8O3 perovskite-type oxides were examined in the LiOH–LiCl electrolyte. The perovskite-type oxides were stable in this solution and the oxygen reduction and evolution overpotential on the carbon black substrate was decreased by addition of these perovskite-type oxides. No chlorine evolution was observed during the oxidation reaction on carbon black with the perovskite-type oxides in the LiOH–LiCl electrolyte. The results indicate that carbon black with perovskite-type oxide additives is a potential candidate for the air electrode in the aqueous electrolyte lithium-air rechargeable batteries.

► Catalytic activity of perovskite-type oxides were examined in LiOH–LiCl electrolyte. ► Chlorine gas was not evolved during charge process. ► These oxides were chemically and electrochemically stable in the electrolyte.