A Sb2S3 Nanoflower/MXene Composite as an Anode for Potassium-Ion Batteries

Potassium-ion batteries (PIBs) are prospective for energy storage systems owing to their low price and high operating voltage. Antimony-based electrode materials have the advantage of high capacity for PIBs, while suffering from huge volume expansion and inferior stability because of the large radius of K+. Therefore, developing suitable antimony-based electrode materials with high performance is highly challenging. Herein, self-assembled Sb2S3 nanoflowers on the surfaces of MXene (Ti3C2) flakes are synthesized through a solvothermal reaction along with a calcination method. The highly conductive two-dimensional Ti3C2 soft substrate could not only boost the charge transfer kinetics but also buffer the volumetric expansion of Sb2S3 effectively. In addition, the structural stability is enhanced because the Sb2S3 nanoflowers are in situ grown on Ti3C2 flakes through the strong interfacial coupling. Consequently, the Ti3C2-Sb2S3 anode exhibits a high reversible capacity of 461 mAh g(-1) at 100 mA g(-1), long cycling life (capacity retention of 79% for 500 cycles), and superior rate performance (102 at 2000 mA g(-1)). This work may provide a pathway for designing advanced materials for PIBs.