LaNixCo1-xO3-delta Perovskites as Catalyst Material for Non-Aqueous Lithium-Oxygen Batteries

초록

The oxygen electrode is a vital element in developing lithium-oxygen batteries, because it provides the active sites for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In addition, the performance of the oxygen electrode strongly depends on the activity and architecture of materials employed. Perovskite oxide nanostructures of nickel-doped lanthanum cobaltite were prepared by a very simple and cost-effective solution combustion synthesis. The oxygen electrode containing a carbon-supported perovskite oxide catalyst with oxygen vacancies exhibited reduced polarization and improved discharge capacity compared with that containing only bare carbon without a catalyst. In particular, the LaNi0.25Co0.75O3-d catalyst showed the best catalytic activity for OER by achieving the oxidation of Li2O2 at 3.8 V. The widespread dispersion and mesoporous design of perovskite facilitates the diffusion of electrolyte and oxygen into the inner electrode to demonstrate cyclability for 49 cycles while maintaining a moderate specific capacity of 1000 mAh g(-1). Further, the synergistic effect of the fast kinetics of electron transport provided by the carbon support and the high electro-catalytic activity of the perovskite oxide resulted in excellent performance of the oxygen electrode for Li-O-2 batteries. (C)