Investigation Mo-based Anode Materials For Lithium/Sodium-ion Batteries

Graphene has low theoretical capacity of 372 mAh g^-1,cannot meet the growing demand of society.Nanostructured materials have been extensively explored in various fields of energy storage and conversion due to its large specific surface area and good physicochemical properties.Transition metal Mo-based compounds attract researchers’interest because of their good thermal stability and high theoretical capacity.Therefore,here,many works to improve the cycle performance and conductivity of Mo-based compounds have made and the research results and conclusions are as follows:The LIBs anode MoO₂@MoS₂/S-doped graphene foam was prepared via hydrothermal and sulfurization reaction.The binderless electrode prevents the separation of the electrode material from current collector during the cycle and improves the stability of the material.The result indicated that the composite material obtained with 0.05 g S has the best performance.It exhibits a reversible capacity of 683 mAh g^-1 in the initial cycle at the current density of 0.1 A g^-1 and maintains 533 mAh g^-1 after 350 cycles at a current density of 0.5 A g^-1.Therefore,the electrodes show good cycling stability.The sodium ion battery（SIBs）anode material with MoS₂/carbon fibers was scientifically designed by hydrothermal reaction and accompanied by calcination in air.In this work,the synergistic effect of oxygen doping and carbon fiber makes the composite have execllent electrochemical properties.Oxygen doped produces a lot of active sites,and the carbon fiber structure contributes to the cycling properties of the material.At a current density of 0.1 A g^-1,the electrode still has a reversible capacity of 330 mAh g^-1after 100 cycles,it indicate the composite has good electrochemical properties.The MoS_2-xSe_x/graphene anode composite was prepared by hydrothermal method and selenization reaction.The conversion of MoS₂ to MoS_2-xSe_x can expand the interlayer spacing,improve the electronic conductivity and produce more defects.Graphene as a conductive network maintains the structural stability during cycling.The ternary MoS_1.2Se_0.8/graphene(MoS_1.2Se_0.8/G)electrode exhibited a high reversible capacity of509 mAh g^-1 after 200 cycles at a current density of 0.1 A g^-1,also show a high reversible capacity of 178 mAh g^-1 after 700 cycles at a current density of 2 A g^-1.The results show that ternary MoS_2-xSe_x composites have excellent electrochemical properties.