Enhanced electrochemical performance of MoS2 for lithium ion batteries by simple chemical lithiation

Commercial MoS2 was lithiated by soaking in butyllithium in argon atmosphere. The lithiated samples (LixMoS2) exhibited greatly improved electrochemical performance. LixMoS2 showed a high reversible capacity of 669.5 mAh g-1 and excellent cycling stability, with an average capacity loss of merely 0.065% per cycle. The rate capability of the LixMoS2 electrode was also improved compared to that of the unlithiated MoS2 electrode. The x-ray diffraction and high resolution transmission electron microscopy (TEM) results prove that there was an increase in the c lattice parameter for the lithiated material. The magnetic properties and evaluations of conductivity in MoS2 and LixMoS2 show that the electric conductivity of LixMoS2 is much higher than that of MoS2. TEM images after 11 cycles demonstrated that the LixMoS2 electrode consisted of more uniform small particles, while big particle blocks could be observed for the MoS2 electrode. All of these might be favourable for the electrochemical performance.