A SbS 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 SbS nanoflowers on the surfaces of MXene (TiC) flakes are synthesized through a solvothermal reaction along with a calcination method. The highly conductive two-dimensional TiC soft substrate could not only boost the charge transfer kinetics but also buffer the volumetric expansion of SbS effectively. In addition, the structural stability is enhanced because the SbS nanoflowers are in situ grown on TiC flakes through the strong interfacial coupling. Consequently, the TiC-SbS anode exhibits a high reversible capacity of 461 mAh g at 100 mA g, long cycling life (capacity retention of 79% for 500 cycles), and superior rate performance (102 at 2000 mA g). This work may provide a pathway for designing advanced materials for PIBs.