Spherical nano Sb@HCMs as high-rate and superior cycle performance anode material for sodium-ion batteries

Abstract Porous and spherical nano Sb@hollow carbon microspheres (Sb@HCMs) composites are prepared by the carbonization of the cultivated yeast cells and the reduction of SbCl 3 in the presence of the carbon spheres. The electrochemical performance of the sodium ion batteries (SIBs) with Sb@HCMs as anode is investigated. After 150 cycles, the Sb@HCMs-50 electrode shows the high reversible capacity of 464 mAh g −1 and 454 mAh g −1 at 0.1 A g −1 and 0.5 A g −1 , respectively. Even the current density reaches up to 3.2 A g −1 , the reversible capacity of 311.5 mAh g −1 can be retained. The Sb@HCMs-50 electrode exhibits the superior cycling and rate performance, which can be ascribed to the carbon frame and the Sb nanocrystals. The carbon frame can release the volume expansion, improve the conductivity, and prevent the agglomeration of Sb nanoparticles. Also, the Sb nanocrystals allow for more Na + storage though the enhanced dissolution of Na in Sb. The simple and efficient synthetic route of Sb@HCMs makes it attractive as anode in advanced SIBs.