Research On Preparation Of Molybdenum Disulfide Anode And Its Electrochemical Performance

Current commercial lithium ion battery anode material is carbon, because theembedded lithium electric potential are close to the deposition potential, easy toproduce lithium dendrite exhalation, and the theory of capacity is not high, fastcharge and discharge performance is poor, cannot meet the needs of rapiddevelopment for li-ion battery with high capacity, fast charge and discharge cycleperformance. Molybdenum disulfide is a type of graphene structure of layeredcompounds and its layers interacted by the van der Waals force, is advantageous toprovide more space for lithium ion embedded. Research about the influence ofstructure and shape on the electrochemical properties of Molybdenum disulfide hasbecome a hot spot. XRD, SEM, TEM, Raman, charge-discharge test, cyclicvoltammograms test and AC impedance test have been carried on from thepreparation, morphology and structure characterization, to the compositemodification and the performance.hydrothermal conditions such as the hydrothermal temperature, themolybdenum source and sulfur source, hydrothermal solvent, surfactant have beenoptimized, finally flowerlike molybdenum disulfide was prepared, and itselectrochemical performance was tested, show the good capacity. Theelectrochemical performance is good. Under50mA/g of current density, initialdischarge capacity of the battery could reach more than1000mAh/g, after50cyclescould still stay at220mAh/g, the battery capacity was high. Battery capacityenhancement may be associated with flower appearance, the organic combination ofnanosheeets, not only increase the surface contact between the electrode and theelectrolyte, provide more space for lithium ions embedded, but also effectivelyshorten the lithium ion migration path.Flowerlike molybdenum disulfide, while with high capacity, cycle performancewas poor, the capacity dropped quickly. Based on the hydrothermal preparation ofmolybdenum disulfide and graphene composites, preparation methods of precursorwere examined. Research results show that after synchronized hydrothermalreduction synthesis of composite materials, the electrochemical performanceimproved obviously, not only the cycle performance is enhanced, but also thebattery capacity is also improved, and with the increasing current density thecirculation performance was still good. Under high current density of200mA/g, thecapacity is still reach735mAh/g after20cycles, initial discharge capacity of thebattery up to more than900mAh/g, the capacity of molybdenum disulfide were466 mAh/g. The improvement of the performance of the composites is related to theexcellent properties of graphene, on the base of molybdenum disulfide with highspecific capacity, graphene is used to enhance the structural stability and improvethe conductivity of the material, thereby enhancing the cycle stability of the battery.