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Ultrasmall SnS Quantum Dots Anchored onto Nitrogen-Enriched Carbon Nanospheres as an Advanced Anode Material for Sodium-Ion Batteries

2020; American Chemical Society; Volume: 12; Issue: 6 Linguagem: Inglês

10.1021/acsami.9b18997

1944-8252

Ganesh Kumar Veerasubramani, Myung-Soo Park, Jin-Yi Choi, Dong‐Won Kim,

Supercapacitor Materials and Fabrication

Structural pulverization of metal chalcogenides such as Sn-based compounds is a serious issue for development of high-performance anode materials and results in serious capacity fading during continuous charge and discharge cycles. In this work, we synthesize ultrasmall SnS quantum dots (QDs) anchored onto nitrogen-enriched carbon (NC) nanospheres through facile hydrothermal and carbonization processes to prepare a progressive anode material for sodium-ion batteries. The optimized SnS QDs@NC electrode delivered an initial discharge capacity of 281 mAh g–1 at 100 mA g–1 and exhibited excellent cycling stability with a capacity retention of 75% after 500 cycles at a high current density of 1000 mA g–1. Ex situ XRD, XPS, FE-SEM, TEM measurements, and kinetics study were performed to unveil the sodium storage mechanism of the SnS QDs@NC electrode. A sodium-ion full cell assembled with an SnS QDs@NC anode and a Na3V2(PO4)3 cathode exhibited high capacity and good cycling stability. Such a superior electrochemical performance of SnS QDs@NC can be attributed to the synergistic effects of NC and SnS QDs where NC serves as a conducting matrix to support SnS QDs and helps avoid structural degradation. This work provides a promising strategy to resolve the pulverization issue of alloying and conversion-type anode materials.