The Preparation And Electrochemical Properties Of Sb-based Carbon Anode Material For Sodium Ion Batteries

In recent years,with the increasing demand for high-power batteries,the traditional carbon anode material has been unable to meet the demands of the market.Antimony-based materials with theoretical high capacity,low sodium potential,which is a new type of sodium-ion anode material,having a good prospect.However,the storage mechanism of the alloy anode material in the discharge/charge process is that the metal antimony / tin element has high reversibly alloyed and dealloyed to work.The main drawback is that the large volume expansion caused by the sodium ion diacharge/charge process leads to the mechanical pulverization,thereby reducing electrical contact between the active material and the electrode,deteriorating the cycle stability.In this paper,Sb and SnSb materials are the research direction,and the reasonable structure is designed to meet the commercial requirements for the problems of poor conductivity and large volume expansion.The specific research contents are as follows:?1?Using the black fungus as the raw material,the biomass carbon precursor was prepared by using hydrothermal synthesis method,and the porous biomass carbon with large specific surface area was synthesized by high temperature calcination method.SbCl₃ was used as the antimony source,antimony nanoparticles were deposited on the porous biomass carbon by liquid phase chemical reduction using sodium borohydride as the reducing agent and ethanol as the solvent.The samples were characterized by XRD,structure and other characterization,and test the electrochemical performance of sodium-ion battery.The composites have a high reversible capacity of 566.7 mAh g-1at a current density of 100 mA g-1 and a good cycle stability after 250 cycles.The effects of different doping carbon materials on the electrochemical properties of the composites were investigated.?2?Sb / rGO nanocrystals were prepared by liquid phase chemical reduction using sodium borohydride as the reducing agent and CTAB as the surface agent using SbCl₃ as the antimony source,and the excellent graphene?GO?was prepared by the improved Hummers method.XRD,morphology and structure were used to characterize the electrochemical properties.?3?The precursor SnSbOx / CNT were prepared by hydrothermal synthesis of high temperature and high pressure using carbon nanotubes?CNT?as the carbon source,Sb?CH3COO?3 as the antimony source and SnCl2 · 2H2 O as the tin source.Sn Sb / CNT nanocomposites were prepared to study the effect of heat treatment at different temperatures on the morphology and properties,and the composite exhibited a high reversible capacity of 534 mAh g-1,and the capacity was 477.2 mAh g-1after 100 cycles.