Electrochemical cycling reversibility of LiMoS2 using first-principles calculations

A static computational model based on chemical hardness is proposed for the prediction and modification of the electrochemical cycling reversibility in Li-ion battery electrode materials. As an example, it is demonstrated that the cycling reversibility of high capacity anode material LiMoS2 is governed by a principle of maximum hardness, which correlates ion rearrangement with the hardness of electron transfer, accompanying the formation of charge density wave. Using the model, we show that the modifications or doping that soften the hardness of electron transfer of MoS2 (e. g., electron-donor doping) can promote Li ion extraction and improve the electrochemical cycling reversibility. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731209]