LAUSR

The electrochemical comparison between Sb2S3 and its composite with carbon (Sb2S3/C) involved by sodium ion carrier are explained by enhanced kinetics, particularly with respect to improved interfacial conductivity by surface modulation by carbon. Sb2S3 and Sb2S3/C are synthesized by a high energy mechanical milling process. The successful synthesis of these materials is confirmed with X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM). As an anode material for sodium ion batteries, Sb2S3 exhibits an initial sodiation/desodiation capacity of 1,021/523 mAh g-1 whereas the Sb2S3/C composite exhibits a higher reversible capacity (642 mAh g-1). Furthermore, the cycle performance and rate capability of the Sb2S3/C composite are estimated to be much better than those of Sb and Sb2S3. Electrochemical impedance spectroscopy analysis shows that the Sb2S3/C composite exhibited charge transfer resistance and surface film resistance much lower than Sb2S3. X-ray photoelectron spectroscopy analyses of both electrodes demonstrate that NaF layer on Sb2S3/C composite electrode leads to the better electrochemical performances. In order to clarify the electrochemical reaction mechanism, ex-situ XRD based on differential capacity plots and ex-situ HR-TEM analyses of the Sb2S3/C composite electrode are carried out and its reaction mechanism was established.