The Preparation Of Zinc Sulfide And Its Application In The Sodium Ion Batteries

With the increasingly serious energy situation and the increasing emphasis on environmental issues.It is noted that both sodium ion battry reversible charging/discharging process.Moreover,the reserves of sodium resources are enormous.So sodium ion batteries are considered to be very promising energy reserve systems.Among various kinds of metal sulfides,zinc sulfide(ZnS)has been widely used in the electrochemistry for its advantages of low voltage platform and low cost.We began to try to synthesize smaller nanomaterials,design a variety of nanostructures and composite with carbonaceous material.Three composite materials based on zinc sulfide were synthesized.(1)We successfully synthesized uniformly dispersed ZnS quantum dots(QDs)on graphene nanosheets via a facile hydrothermal method.The prepared ZnS/graphene composites was studied as a dual anode for sodium-ion.Tested against SIBs,the nanocomposites exhibits an impressive specific capacity of 491 mAh/g at 100mA/g after 100 cycles.(2)We report a facile and low-energy strategy to synthesize ZnS quantum dots with graphene composites.First,we prepare zeolitic imidazolate frameworks(ZIF-8)and graphene composites by stirring at room temperature.Then,the ZnS quantum dots and graphene composites is obtained by refluxing.The ZnS/GAs is tested for SIBs;the capacity is still stable at 539mAh/g at 100mA/g after 100 cycles.Even when the current density is increased to lA/g,the capacity can still reach 362mAh/g after 300 cycles.(3)Firstly,ZnS nanospheres with rough surface were synthesized,then a layer of Si02 layer was coated and a layer of resorcinol-formaldehyde layer was coated on the outermost layer.After carbonization at high temperature,the Si02 layer is etched away with NaOH solution,Frog egg-like core-shell structure of zinc sulfide(ZnS@Void@C)can be obtained.The ZnS@Void@C is tested for SIBs;the capacity is still stable at 539mAh/g at 100mA/g after 100 cycles.Even when the current density is increased to 5A/g,the capacity can still reach 205mAh/g after 900 cycles.