Theoretical Investigation of Li and Na Oxides Adsorption on TiC(111) Surface for Metal-Air Rechargeable Batteries

We analyze, with Density Functional Theory (DFT) calculations, the adsorption energies of Li$_2$O$_2$, Na$_2$O$_2$ and NaO$_2$ on clean and oxygen passivated TiC (111) surfaces. We show, that after deposition of two molecular layers of alkali metal oxides, the initial state of the TiC surface becomes unimportant for the adsorption energy and that all adsorption energies approach their native crystal values. The structure of the adsorbed molecular layers is analyzed and compared to their native oxide crystal structure. Finally, we discuss the possible implications for electrode optimization for Li-air and Na-air batteries.