NANOALLOY-BASED ELECTROCATALYSTS IN RECHARGEABLE LITfflUM-AIR BATTERIES

摘要

Non-aqueous and rechargeable lithium-oxygen batteries promise a 10-fold increase of energy capacities in comparison with current lithium ion batteries. However, there are major challenges, including the unacceptable high voltages for the discharge-charge processes and the difficulty to achieve an optimal balance between the discharge capacity and the capacity retention on "discharge-charge" cycling at the cathode. The need of a catalyst in the air cathode to reversibly reduce oxygen and re-oxidize the oxide species back to oxygen largely stems from addressing the large overpotentials in the discharge-charge reactions, i.e., the oxygen reduction reaction (ORR) on discharge and the oxygen evolution reaction (OER)) on charge (Figure 1).