Carbon skeleton confined Sb chalcogenides nanodots for stable sodium storage

Antimony-based materials represent promising anode materials for sodium ion batteries (SIBs) owing to their high theoretical capacity, however, the large volume expansion and low ionic conductivity during the electro-chemical process prohibit them from reaching their theoretical expectations. In this work, Sb2S3@C and Sb2Se3@C nanodots with uniform diameters of 19.0 nm and 20.7 nm were synthesized by H-2/C thermal reduction and co-sulfurization (selenization) of sodium stibogluconate. Each Sb2S3 and Sb2S3 nanodot was coated by an interconnecting carbon network with weak graphitization, which further crosslinked together to form a high conductive framework. When applied as anode for SIBs, they exhibited desired sodium storage properties, especially the excellent cycling stability of Sb2S3@C nanodots with a reversible capacity of 316.1 mA h g(-1 )after 100 cycles at 100 mA g(-1 ) and 269.1 mA h g(-1 ) after 200 cycles at 1 A g(-1 ), which was consistent with the calculated result of theoretical volume changes (264% and 246%) and density functional theory (DFT) calculation for both materials during the Na+ intercalation processes, as expected.

Automated summary

Antimony-based materials, such as Sb2S3@C and Sb2Se3@C nanodots, show promising potential as anode materials for sodium ion batteries due to their high theoretical capacity. In this study, nanodots with uniform diameters were synthesized and coated with a carbon network to improve conductivity. The Sb2S3@C nanodots exhibited excellent cycling stability after 100 cycles, making them a desirable choice for battery applications.