A New rGO-Overcoated Sb2Se3 Nanorods Anode for Na+ Battery: In Situ X-Ray Diffraction Study on a Live Sodiation/Desodiation Process

TLDR: In this paper, Sb2Se3 nanorods uniformly wrapped by reduced graphene oxide (rGO) as a promising anode material for SIBs are reported, which yields a high reversible mass-specific energy capacity of 682, 448, and 386 mAh g−1 at a rate of 0.1, 1, 1.0, and 2.0 A−1, respectively.

Abstract: Sodium ion batteries (SIBs) are a promising alternative to lithium ion batteries for a broader range of energy storage applications in the future. However, the development of high-performance anode materials is a bottleneck of SIBs advancement. In this work, Sb2Se3 nanorods uniformly wrapped by reduced graphene oxide (rGO) as a promising anode material for SIBs are reported. The results show that such Sb2Se3/rGO hybrid anode yields a high reversible mass-specific energy capacity of 682, 448, and 386 mAh g−1 at a rate of 0.1, 1.0, and 2.0 A g−1, respectively, and sustains at least 500 stable cycles at a rate of 1.0 A g−1 with an average mass-specific energy capacity of 417 mAh g−1 and capacity retention of 90.2%. In situ X-ray diffraction study on a live SIB cell reveals that the observed high performance is a result of the combined Na+ intercalation, conversion reaction between Na+ and Se, and alloying reaction between Na+ and Sb. The presence of rGO also plays a key role in achieving high rate capacity and cycle stability by providing good electrical conductivity, tolerant accommodation to volume change, and strong electron interactions to the base Sb2Se3 anode.