Carbon Hollow Tube-Confined Sb/Sb2S3 Nanorod Fragments as Highly Stable Anodes for Potassium-Ion Batteries

Potassium-ion batteries (PIBs) have attracted widespread attention in recent years due to their potential advantages such as low cost and high energy density. However, the large radius of K+ and the low potassium storage capacity of some electrode materials limit their development. Antimony (Sb)-based materials are considered to be promising anode materials for PIBs in view of their high K storage capacity and low potassiation potential. Nonetheless, the huge volume variation caused by potassiation/depotassiation often leads to their failure. Previous works have proved that carbon coating and nanostructure design are important means to alleviate the volume effect. Herein, the carbon-coating technology and nanostructure design were combined to prepare a Sb-based nanomaterial with Sb/Sb2S3 hybrid nanorod fragments confined in a carbon hollow tube (Sb/Sb2S3@CHT). Such a nanostructure is beneficial to alleviate the volume change of the Sb/Sb2S3 hybrids while facilitating the kinetics of the electrochemical reaction. As a consequence, the Sb/Sb2S3@CHT anode electrode exhibits high rate performance and outstanding cycle stability characterized by retaining a high specific capacity of 400.9 mA h g(-1) after cycling for 200 cycles at 200 mA g(-1).

Automated summary

Antimony-based materials are promising anode materials for potassium-ion batteries due to their high potassium storage capacity and low potassiation potential, but volume variation issues can lead to instability. Carbon coating and nanostructure design can alleviate this problem and improve the performance of the electrode.