Study On Preparation Of Bismuth-based Anode Materials By Arc Discharge And Its Sodium Storage Properties

With the large-scale development of lithium ion batteries industry,the demand for lithium is also increasing.However,due to the shortage and uneven distribution of lithium in the earth’s crust,its price has soared.In view of this,the development of other battery technologies is crucial,and the abundance,wide distribution and many similar physical and chemical properties to lithium of sodium make sodium-ion batteries a promising candidate.Bismuth-based materials have been widely used as anodes for alkali ion batteries because of their high theoretical specific capacity and suitable working potential.However,the problem of volume expansion has been difficult to be solved.Designing reasonable nanostructures for anode materials,or coating them with elastic carbon layers,on the one hand can ensure fast dynamics and on the other hand can effectively alleviate the stress/strain caused by material volume changes,therefore,in this work,we step through synthesized carbon coated Bi₂Se₃nanoparticles and Bi₂Te₃ nanoparticles by DC arc discharge,and put them as sodium ion battery anode materials（SIBs）.The reversible specific capacity of Bi₂Te₃/C is still280 m Ah g^-1 after 500 cycles at a high current density of 10 A g^-1;The Bi₂Se₃/C anode still has a reversible specific capacity of 370 m Ah g^-1 after 1400 cycles at a current density of 10 A g^-1.In addition,even at a super current density of 40 A g^-1,the specific charge capacity remains at 320 m Ah g^-1 after 500 cycles with almost no attenuation.Cyclic voltammetry and in situ X-ray powder diffraction were used to study the mechanism of Na⁺storage.Combined with a simple synthesis method and excellent electrochemical performance,Bi₂Se₃/C and Bi₂Te₃/C composite materials have the prospect of practical large-scale application.