Carbon-Supported Metal Oxide Nanoparticles As Electrocatalysts for the Oxygen Reduction Reaction in Li-O2 Batteries

Abstract

Oxygen reduction reactions (ORR) at the O2 cathode in nonaqueous electrolytes are known to influence the performance of Li-O2 batteries. In this work, we created two ordered mesoporous MnOx/C and TiO2/C composites by a simple hydrothermal process. The composites were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, small angle X-ray scattering, BET measurements, galvanostatic charge-discharge methods. Their ORR kinetics and mechanism have been investigated in Li-O2 batteries by using the rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) measurements. The electrochemical tests indicate that the MnO2/C composites have excellent catalytic activity towards ORR due to the larger surface area of order mesoporous carbon and higher catalytic activity of MnO2.