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

TL;DR

This study uses DFT calculations to analyze how Li and Na oxides adsorb on TiC(111) surfaces, providing insights into electrode behavior for metal-air batteries and how adsorption energies relate to native crystal structures.

Contribution

It offers a detailed theoretical analysis of alkali metal oxide adsorption on TiC surfaces, highlighting the transition to native crystal-like adsorption energies after two molecular layers.

Findings

Adsorption energies approach native crystal values after two molecular layers.

Surface initial state becomes irrelevant after deposition of two layers.

Structural analysis compares adsorbed layers to native oxide crystals.

Abstract

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.