Adsorption and Deposition of Li2O2 on TiC{111} Surface

A recent experimental study from Bruce's group demonstrated the feasibility of TiC as a cathode material for Li air battery. We investigate Li2O2 adsorption and deposition on TiC{111} surface by periodic density functional theory calculation. The results showed that, upon interaction with Ti-terminated TiC{111} surface, Li2O2 clusters reassembled into a saturated periodic two atomic layer coating in which each O atom was bonded to three Ti atoms to form a O layer equivalent to the layer formed by O2 surface oxidation, and the Li atoms sat on the top. The atomic arrangement of O and Li layers is the same as that of O2Li1 layers normal to ⟨0001⟩ direction in Li2O2 crystal structure. Interface models constructed based on this lead showed that the growth of Li2O2 can be continued through a surface conduction mechanism to form Li2O2 coating with lattice parameters almost identical to those of the standard Li2O2 unit cell. The results support the experimental discovery from Bruce's group.