| Lithium-ion batteries have attracted wide attention due to their long cycle life,high energy density and high voltage.However,with the increasing demand for constant power supply,there is still a need to develop new electrode materials with better performances.It is generally believed that the electrochemical processing of the battery is closely related to the microstructure of the electrode material.In particular,since the electrode material of the nanostructure itself has a short diffusion distance of electrons and lithium ions,the active location in the material is rich and the contact area between the electrode material and the electrolyte solution is high,the rapid development of nanotechnology and nanotechnology in recent decades,have always led to the production of various functional materials.Because of its layered structure,transition metal oxides can facilitate the intercalation of lithium ions by providing a wide range of binding sites.Therefore,in the past ten years,research on nanostructured transition metal oxides as electrode materials for lithium-ion batteries has made considerable progress.Among various transition metals,MoO3 has shown great potential as a negative electrode material because of its higher theoretical specific capacity(～1117 mAh·g-1),but at the same time MoO3 also has disadvantages such as volume expansion.We have innovatively constructed a new 3D nanosheet structure of a-MoO3,and improved the above shortcomings of MoO3 by constructing composite materials with molybdenum disulfide and high bio-carbon materials.This method is used for research on molybdenum-based electrode materials.The method is applied to the study of molybdenum electrode materials.Has a very important meaning.The work mainly includes the following three contents.(1)Using molybdenum acetylacetonate(MoAc)as the molybdenum source,tetrahydrofuran(THF)as the solvent,and H2O2 as the morphology control agent,3D nanosheet petal-like MoO3 was prepared by one-step solvothermal method,and the reaction temperature,reaction time and hydrogen peroxide were changed.The morphology and electrochemical performance of the prepared MoO3 were studied with the addition amount and other parameters.The results showed that when used as the negative electrode material of lithium-ion batteries,3D MoO3 nanosheets exhibit high reversible capacity and long-cycle stability.The reversible capacity is 555 mAh·g-1 at 0.5 A·g-1,and it maintains 214.7 mAh·g-1 after 600 cycles at a current density of 1 A·g-1.(2)To further improve the electrochemical performance of the 3D nanosheet structured MoO3,we use thiourea(TS)as the sulfur source and the synthetic petal-like MoO3 matrix to construct the MoO3@MoS2 composite material,so that the MoS2 is successfully loaded onto the MoO3 sheet and the sulfur is changed.The morphology and electrochemical performance of the prepared petal-like MoO3@MoS2 composites were studied with the addition amount of urea and solvents.The results showed that the capacity and cycle stability of MoO3@MoS2 were significantly improved compared to MoO3.Among them,the composite material has a reversible capacity of 760.3 mAh·g-1 after cycling at high current density.(3)In order to improve the low conductivity of 3D nanosheet structure MoO3,we add pretreated bio-carbon material rice(RC)as a carbon source in the hydrothermal process of MoO3,successfully synthesized RC/MoO3 composite material,then introduce reduced graphene oxide into RC/MoO3 composites through self-assembly,successfully prepared RC/MoO3@rGO electrode materials,and studied the influence of the addition of RC and reduced graphene oxide on the electrochemical performance of MoO3.The results show that the introduction of RC significantly improves the capacity and cycle stability of the material,while the addition of graphene further optimizes the electrochemical performance of the material,so that the capacity of the material can be maintained at 378.7 mAh·g-1 after a long cycle of 2000 cycles. |
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