  Based on ab initio calculations, we examine the incorporation of Li atoms in
the MoS2/graphene interface. We find that the intercalated Li atoms are
energetically more stable than Li atoms adsorbed on the MoS2 surface. The
intercalated atoms interact with both graphene sheet and MoS2 layer, increasing
the Li binding energies. However, the equilibrium geometries are ruled by the
MoS2 layer, where the intercalated Li atoms lie on the top (Li_T) and hollow
(Li_H) sites of the MoS2 layer. We calculate the Li diffusion barriers, along
the Li_T -> Li_H diffusion path, where we find similar energy barriers compared
with that obtained for Li adatoms on the MoS2 surface. Our results allow us to
infer that the Li storage capacity increases at MoS2/G interfaces, in
comparison with Li adatoms on the MoS2 surface, however, with no reduction on
the mobility of the intercalated Li atoms. Those properties are
interesting/useful to the development of Li batteries based on MoS2.
