Effect of multi-catalysts on rechargeable Li–air batteries

• A multi-catalyst system (Co3O4 and LiI) was used for enhanced Li–air battery cells.
• LiI was effective in decreasing the overpotential and to improve the cyclic performance of the cell.
• The multi-catalyst system is superior to a single catalyst system using either LiI or Co3O4.
• LiI also affects the surface morphology of the electrode and the crystallinity of Li2O2.

Oxide catalysts such as MnO2 and Co3O4 are effective in improving the electrochemical performance of the air electrode of a Li–air cell. However, it is difficult to bring the oxide catalyst into homogeneous contact with the reaction products formed during the discharge process. To overcome this problem and to enhance the performance of Li–air cells, an oxide catalyst and an additionally dissolved catalyst (LiI) were used in combination. LiI dissolved in an electrolyte can freely access and react with solid reaction products, thereby facilitating their catalytic decomposition. In this study, the electrochemical performance of an air electrode in combination with a pristine and a LiI-dissolved electrolyte system was characterized and compared. Analysis of the surface morphology of the air electrode before and after cycling along with the phases of the reaction products was conducted.