Research Of Electrochemical Performance Of Bi-based Materials On The Anode Of Sodium Ion Batteries

With the exhaustion of fossil fuels,global warming and environmental pollution,it becomes particularly important to develop and using new types of sustainable energy sources is the replace traditional energy sources.However,the common sustainable resources are volatile and it can not be directly sent to the grid.Therefore,it is an ideal method to develop energy storage systems with high comprehensive cost-effectiveness.At present,sodium ion batteries have become one of the most promising candidates to meet this requirement as a cheaper and effective energy storage device.Bismuth-based materials have involved unique Bi layered crystal structure and high theoretical specific capacity of>300 mAh g^-1Therefore,bismuth metal materials have been proven to be promising high-performance anode materials.It improve the electrochemical performance of bismuth-based materials in anode materials for sodium ion batteries.The paper use bismuth-based compounds and composite materials increase the storage site of sodium ions and the stability of the material.This article explores that the monoclinic bismuth phosphate materials are more suitable for sodium ion battery anode materials.The composite material of bismuth phosphate and reduced graphene oxide is synthesized by a hydrothermal method.The analysis of this material by various morphological characterization methods XRD,SEM,TEM and various electrochemical test methods.Such as AC impedance test and discharge and cyclic voltammetry.It improved the resistance of the main body and have an excellent specific capacity of 450 mAh g^-1 at a current density of 100 mA g^-1 after 200 cycles.Moreover,the bismuth sulfide material in this paper is synthesized by the same one-step hydrothermal synthesis as the bismuth phosphate.It is calcined with selenium powder at a high temperature under the protection of an argon-hydrogen?hydrogen less than 5%?mixture.the Se-doped bismuth sulfide composite has higher stability by reduced graphene oxide material.It has been shown by electrochemical performance testing methods such as constant current charge and discharge and cyclic voltammetry The doping of Se powder improve the stability to a certain extent,and the initial Coulomb efficiency reached more than 65%.And at a current density of 100 mA g^-1,the specific capacity reached an excellent 800 mAh g^-1or more in 100 cycles.At the same time,it have 912mAh g^-1and 703 mAh g^-1specific capacity at the different current density of 100 mA g^-1and 1000 mAh g^-1.