Construction of ZnS/Sb2S3 Heterojunction as an Ion-Transport Booster toward High-Performance Sodium Storage

Metal sulfides have shown great promise for sodium-ion batteries due to their excellent redox reversibility and relatively high capacity. However, metal sulfides generally suffer from sluggish charge transport and serious volume change during the charge-discharge process. Herein, potato chip-like nitrogen-doped carbon-coated ZnS/Sb2S3 heterojunction (ZnS/Sb2S3@NC) is precisely synthesized through a sulfurization reaction, and a subsequent metal cation exchange process between Zn2+ and Sb3+. The theoretical calculations and experimental studies reveal the boosted charge transfer in ZnS/Sb2S3@NC composites. Therefore, the ZnS/Sb2S3@NC electrode exhibits excellent cycling stability (a high reversible capacity of 511.4 mAh g(-1) after 450 cycles) and superior rate performance (400.4 mAh g(-1) at 10 A g(-1)). In addition, ZnS/Sb2S3@NC is based on a conversion-alloy reaction mechanism to store Na+, which is disclosed by the X-ray diffraction and high resolution transmission electron microscopy analysis. This effective synthesis method can provide a reference for the design of other high-performance electrode materials for sodium-ion batteries.