Study On The Synthesis And Electrochemical Performance Of Antimony Based Nanomaterials

With the development of science technology and the rapid consumption o f fossil energy,lithium ion battery plays the key role in energy storage devices in recent years.How to make electrode materials with the advantages of high energy density,favourable safety performance,long-circulation,stable voltage platform,high current charge(discharge)becomes the focus of researchers.Sb-based materials are relatively abundant in natural resources.They have a high theoretical capacity(660 m Ah/g)and the safe intercalation lithium potential as the negative electrode of LIBs.All these make them become one of the first choices of LIBs electrode materials.However,there are major problems during the charge and discharge processes(the large volume change,the fast deceeased capacity).Therefore,in this paper,antimony selenide(Sb₂Se₃)and antimony sulfide(Sb₂S₃)were studied to improve the performance of lithium ion batteries by combining with carbon materials and doping atoms.The specific work is as follows:We fabricated 150-200 nm Sb₂Se₃@C nanofibers(Sb₂Se₃@CNFs)by electrospinning method,and the Sb₂Se₃average crystallite sizes is 26.81 nm.We made the three simples Sb₂Se₃@CNF-500/600/700 at different temperatures.It's been tested and studied that Sb₂Se₃@CNF-600 delivered the remarkably performance,at current density of 100 m A/g the discharge capacity remains 625 m Ah/g after 100 cycles and at current density of 1 A/g the discharge capacity is 437 m Ah/g after 500 cycles.Because the N-doped carbon nanofibers can not only solve the problem of volume expansion,but also enhance the conductivity,shorten the diffusion distance,the performance of Sb₂Se₃@CNF-600 is better than others.The significance of this work is to provide ideas for the application of Sb₂Se₃ in other devices.We synthesized Sb₂S₃ nanorods by hydrothermal method and added sulfur powder during annealing after coating them with resorcinol-formaldehyde.Finally,we obtained the sulfur-doped Sb₂S₃ carbon(S-Sb₂S₃@C)nanotubes.Because of the special structure of one dimensional nanotubes,the existence of doped S atom and the high theoretical capacity of Sb₂S₃,the S-Sb₂S₃@C nanotubes used in LIBs are more likely to be in contact with the electrolyte,increase the active site s,then show the excellent performance:the first discharge specific capacity is 929.5 m Ah/g at current density of 200 m A/g,and it still had 609.5 m Ah/g discharge specific capacity after100 cycles,while had the average discharge capacity of 609.5 m Ah/g under the condition of high current density of 2A/g.