Formation/Decomposition of Li 2 O 2 Induced by Porous NiCeO x Nanorod Catalysts in Aprotic Lithium-Oxygen Batteries.

To realize the utilization of high-performance lithium-oxygen batteries (LOBs), a rational-designed cathode structure and efficient catalytic materials are necessary. However, side products accumulated during battery cycling seriously affects the performance. Designing a cathode catalyst that could simultaneously facilitate the catalytic efficiency of the main reaction and inhibit the side reactions will make great sense. Herein, NiCeO _x was proposed for the first time as a bifunctional cathode catalyst material for LOBs. The combined action of NiO and CeO ₂ components was expected to facilitate the decomposition of byproducts (e.g., Li ₂ CO ₃ ), increase the oxygen vacancy content in CeO ₂ , and enhance the adsorption of oxygen and superoxide. NiCeO _x nanorods (NiCeO _x PNR) were prepared using electrospinning method. It showed a hollow and porous nanorod (PNR)-like structure, which provided a large number of catalytic active sites and facilitated the transport of reactants and the deposition of discharge products. As a result, a high specific discharge capacity (2175.9 mAh g ^-1 ) and a long lifespan (67 cycles at 100 mA g ^-1 with a limited capacity of 500 mAh g ^-1 ) were obtained.