Long-life SnS/TiO2/C stemming from nano-TiO2 @C complex hull as Li-ion battery anode

Abstract

SnS, out of high theoretical capacity, is lifted as one of the promising candidates for Li-ion battery anodes. However, restrictions stemming from unsatisfying Li+/electron transferring, serious polarization, huge volume expansion/shrinkage and irreversible capacity loss during the first cycle prevent it from ideal cycling performance and rate property. Herein, a new-building three-nested SnS/TiO2/C (SSTC) hollow box is established, in which TiO2/C double protective hulls well enfold SnS-nanosphere-formed hierarchy-hollow box to form a sandwich-shaped complex wall. By combining heterogeneous interface and hollow cube structure, the SSTC with small amount of TiO2 (SSTC1) can deliver a discharge capacity of 638 mAh g−1 after 200 cycles at 0.2 A g−1. Moreover, it exhibits better rate performance of 1162, 617, 488, 387, 287 mAh g−1 at 0.1, 0.2, 0.5, 1 and 2 A g−1, respectively, and restores to 524 mAh g−1 when the current density decreases to 0.1 A g−1 again. The better electrochemical performance for SSTC is mainly ascribed to the strengthened structural stability and the improved electrical conductivity, which come from three nested SnS/TiO2/C hollow box structure with sandwich-shaped complex wall.