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

Porous and spherical nano [email protected] carbon microspheres ([email protected]) composites are prepared by the carbonization of the cultivated yeast cells and the reduction of SbCl3 in the presence of the carbon spheres. The electrochemical performance of the sodium ion batteries (SIBs) with [email protected] as anode is investigated. After 150 cycles, the [email protected] 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 [email protected] 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 [email protected] makes it attractive as anode in advanced SIBs.