ELECTROCHEMICAL STUDIES OF DISORDERED MOS2 AS CATHODE MATERIAL IN LITHIUM BATTERIES

In this work we report the effect of structural disorder on the storage-charge capacity, reversibility and rate of lithium diffusion in MoS2. The electrochemical properties of the disordered MoS2 are studied in a solid-state cell of type a-MoS2-lithium borate glass-Li and compared with the crystalline form C-MoS2. Cyclic voltammetry of the sample shows good reversibility for lithium intercalation-deintercalation processes. The cell is discharged and charged more than 120 times. In each cycle a slight increase in cell impedance is observed. However, the overall voltage drop after 120 cycles is less than 200 mV. Electrochemical titration of LixMoS2 indicates a significant increase in storage-charge capacity of the disordered MoS2 compared with that of the crystalline sample. Potential step polarization techniques are used to deduce the diffusivity of lithium in LixMoS2. A high lithium diffusion coefficient is observed at low concentration.