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

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.