Pyridine-regulated Sb@InSbS3 ultrafine nanoplates as high-capacity and long-cycle anodes for sodium-ion batteries

Sb-based materials exhibit considerable potential for sodium-ion storage owing to their high theoretical capacities. However, the bulk properties of Sb-based materials always result in poor cycling and rate performances. To overcome these issues, pyridine-regulated Sb@InSbS3 ultrafine nanoplates loaded on reduced graphene oxides (Sb@InSbS3@rGO) were designed and synthesized. During the synthesis process, pyridine was initially adopted to coordinate with In3+, and uniformly dispersed In2S3 ultrafine nanoplates on reduced graphene oxide were generated after sulfidation. Next, partial In3+ was exchanged with Sb3+, and Sb@InSbS3@rGO was obtained by using the subsequent annealing method. The unique structure of Sb@InSbS3@rGO effectively shortened the transfer path of sodium ions and electrons and provided a high pseudocapacitance. As the anode in sodium-ion batteries, the Sb@InSbS3@rGO electrode demonstrated a significantly higher reversible capacity, better stability (445 mAh·g−1 at 0.1 A·g−1 after 200 cycles and 212 mAh·g−1 at 2 A·g−1 after 1200 cycles), and superior rate (210 mAh·g−1 at 6.4 A·g−1) than the electrode without pyridine (355 mAh·g−1 at 0.1 A·g−1 after 55 cycles and 109 mAh·g−1 at 2 A·g−1 after 770 cycles). Furthermore, full cells were assembled by using the Sb@InSbS3@rGO as anode and Na3V2(PO4)3 as cathode, which demonstrated good cycling and rate performances and exhibited promising application prospects. These results indicate that adjusting the microstructure of electrode materials through coordination balance is A·good strategy for obtaining high-capacity, high-rate, and long-cycle sodium storage performances.