Facile Synthesis Of ZnS/rGO Nanocomposites And Applications In Lithium-ion Batteries

Until now,energy play an very important role in our life,more and more researchers focus on the energy storage device to improve the performance of device.As we know,lithium ion battery is most popular secondary battery.However,traditional lithium battery almost can't afford our requirement,so it is very important to make more effort.Anode is a very important part of the battery,the common anode in the marketing is made of graphite,but this kind of anode almost can't be improved,because the capacity has been near the theoretical capacity.Alloy material?oxide material and metal sulfide possess high specific capacity?low price?environment friendly and safety,which are most potential anode material.The defect of this kind of material is that huge volume change between the charge and discharge and low conductivity,which can't take the most advantage of active ingredients.Meanwhile hinder the practical application.Now we take the ZnS as our research object,to overcome the volume change and to improve the conductivity,we have made many efforts.We introduce the graphene material to enhance the conductive.Oxide graphene is equipped with high specific surface and possesses many kinds of oxygen-containing groups,which are attractive to positive ion Zn2+.By the hydrothermal reaction,we get the composite with special structure which is made of hemispherical hollow nano-ZnS particles coating on graphene surface(ZnS/rGO composite).By controlling the temperature and ratio of raw material,we get different morphology ZnS/rGO composite,when ratio get to 1:1,temperature get to 180 ?,the size of the hemispherical hollow nano-ZnS particles is 200 nm,at the current of 100 mAhg-1,the capacity get to 510 mAhg-1.By increase the quantity of reductant of furfuran resin,and high-temperature processing at 600 ?,we reduce the size of ZnS particles to several nanometer,also we can find the carbon layer on the rGO surface.The capacity retain to 714 mAhg-1 after 100 cycles.Add Fe ion solution at the hydrothermal process,we get Fe doped ZnS/rGO composite(ZnS/rGO-Fe).The material keep the same morphology as ZnS/rGO composite in SEM,FeS is found in XRD.The capacity is 600mAhg-1 at 100mAg-1 after 100cycles.We handle our material with sulfur at 155 ?,we get the new composite coated with sulfur layer.To find the influence of ZnS to sulfur battery,we set different ratio of ZnS to GO,we get that when the ratio get to 10:1,the performance is best,capacity get to 921 mAhg-1 after 100 cycles at 0.2 C,the retention rate is 90.5%.