Formation/Decomposition of Li2O2 Induced by Porous NiCeOx Nanorod Catalysts in Aprotic Lithium-Oxygen Batteries.

Abstract

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, NiCeOx 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. NiCeOx nanorods (NiCeOx 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.