A density functional theory study of high-performance pre-lithiated MS(2) (M = Mo, W, V) Monolayers as the Anode Material of Lithium Ion Batteries

Recent experimental study shows that the pre-lithiated MoS(2) monolayer exhibits an enhanced electrochemical performance, coulombic efficiency of which is 26% higher than the pristine MoS(2) based anode. The underlying mechanism of such significant enhancement, however, has not yet been addressed. By means of density functional theory (DFT) calculations, we systematically investigated the adsorption and diffusion behavior of lithium (Li) atoms on the MS(2) (M = Mo, W, V) monolayers. On the pre-lithiated MS(2) monolayers, the adsorption energy of extra Li ions are not significantly changed, implying the feasibility of multilayer adsorption. Of importance, the Li diffusion barriers on pre-lithiated MS(2) are negligibly small because of the charge accumulation between the diffusing Li ions and the pre-lithiating Li layer. Correspondingly, we report that the pre-lithiation should be a general treatment which can be employed on many transition-metal di-chalcogenides to improve their storage capacities and charge-discharge performance in Li ion batteries. In addition, we propose that the pre-lithiated VS(2) may serve as an outstanding anode material in LIBs.