Lithium Storage Performance Of Multicomponent And Lithium-rich Molybdenum Sulfides

Lithium ion battery,as a kind of green energy storage device,is commonly used in communication,power automobile and other fields.The commercial graphite anode materials have good electrical conductivity,but low capacity limits its further development.In order to achieve higher energy density and high voltage of lithium ion battery system,exploring novel negative electrode materials is still one of the core research direction in this field.Transition metal sulfides has high theoretical capacity about 3 to 4 times as much as that of commercial graphite,electron pair effect due to its rich valence,and higher electrochemical reaction activity,thus showing valuable potential as anode materials.However,this kind of material has obvious disadvantage of volume expansion effect,causing serious electrode pulverization limiting its application.This work focuses on the preparation of multi-element molybdenum sulfide through supercritical water system for in-situ carbonization modification,and synthesis of lithium-rich molybdenum sulfide to improve the actual application performance of the full battery system.Here we report ZnMoS4-x compound and associated ZnMoS4-x/C composites synthesized via supercritical water method as anode materials for high capacity Li ion battery.The one-step preparation of ZnMoS4-x compound and ZnMoS4-xC composites employing supercritical water as reaction media is facile,low-cost and environment-benign.Through situ-modifying from glucose carbonization,ZnMoS4-x/C composite with unique nanocoral structural framework retains the large capacity of pure bimetallic sulfides and exhibits improved long-cycle stability as anodes in lithium-ion batteries.Specifically,ZnMoS4-x/C delivers reversible capacity of 931.1 mAh g-1 after 70 cycles at current density of 100 mA g-1.And at high current density of 1500 mA g-1,it also exhibits an excellent capacity of 640.2 mAh g-1 even after 500 cycles.This work would provide a strategy for synthesizing novel multicomponent metallic sulfides electrode materials with high electrochemical performances.Based on synthesis and modification of metallic sulfides,we design an ultra-thin(0.19 nm)lithium-rich molybdenum sulfide LixMoS2/C nano-sheets with high specific capacity of 806 mAh g-1 after 430 cycles.Its low-temperature tolerance is valuable with capacity of 441.0 mAh g-1 under-20℃ after 55 cycles and back to 867.7 mAh g-1 under room temperature.In addition,LixMoS2/C ‖ LiNi0.5Co0.2Mn0.3O2 full cell exhibits superior reversible capacity of 120.9 mAh g-1 after 100 cycles and promising specific energy density of 293.5 Wh kg-1 after 100 cycles.This work might inspire meaningful impact on synthesizing other emerging prelithiation metallic sulfides electrode materials.