Formation/Decomposition of Li₂O₂ 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 CeO₂ components was expected to facilitate the decomposition of byproducts (e.g., Li₂CO₃), increase the oxygen vacancy content in CeO₂, 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.