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

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 MnO_x/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.