Fe2O3 nanorods decorated with ultrafine CeO2 as binder-free cathode to improve the performance of Li-O2 batteries

Abstract The rechargeable Li-O2 batteries have attracted considerable attention in recent years because of their high theoretical energy density. However, the development of Li-O2 batteries is hampered due to the poor cycling performance and high discharge/charge overpotential. In this work, we developed a unique composite of CeO2-decorated Fe2O3 nanorods supported on carbon cloth (Fe2O3/CeO2@CC) as binder-free cathode catalyst. The Fe2O3/CeO2@CC significantly reduced overpotentials for oxygen redox reactions. And their battery could perform to 94 cycles (at 340 mA/g with a limited capacity of 500 mAh/g), which is much better than that of Fe2O3@CC-catalyzed battery (64 cycles). Such well performances should result from that CeO2 catalyst also could serve as oxygen buffer. CeO2 could supply oxygen under deficient conditions and remove oxygen under rich conditions, reducing the interference of oxygen concentration to the battery.