Furthermore we noted that the upper half (un-occupied half of the cone) of the Dirac cone has been completely occupied when we increase the Li concentration in the heterostructure. Since more bands were found to be crossing E f during lithiation, it is obvious that the metallic character of the WS 2 /graphene electrode will be enhanced. Further the careful analysis of band structures also reveals a narrow opening of Dirac bands has occurred when the heterostructure interacts with Li atoms. The extent of band opening was found to be in the range 7.2 to 32.6 meV (refer Figure , Supporting Information). However, it is interesting to note that beyond x = 3, the Dirac cone's position remains nearly the same, or there was no significant shift and also band opening. This could be due to the saturation of charge transfer from Li to graphene beyond that limit (refer Figure ). At the same time more bands from the WS 2 were noticed to be populated below the E f . This implies that Li-WS 2 charge transfer predominates when more Li atoms are introduced into the heterostructure. This is in good agreement with the Bader charge analysis, where we have observed that Q B of graphene varies slightly (= -0.36 to -1.45 e); on the other hand, the same for WS 2 varies much significantly (= -0.64 to -4.54 e). From these findings, we could realize that the Li-atoms prefer WS 2 side (either top site or interface of heterostructure) rather than top of graphene layer. Therefore the Li atoms will occupy the top graphene sites only when the above said sites are completely filled by Li-atoms. In other words, when the number of added Li >18.