Constructing Sb-O-C bond to improve the alloying reaction reversibility of free-standing Sb2Se3 nanorods for potassium-ion batteries

Abstract Sb2Se3 shows some promising potentials for potassium-ion batteries (PIBs) due to its high theoretical capacity induced by conversion and alloying reaction, but the poor alloying reaction reversibility severely limits battery performance. Herein, flexible Sb2Se3 nanorods supported by holey rGO composite membranes (Sb2Se3@h-rGO) are prepared by a direct vacuum filtration and subsequent reduction process, where the pre-electrostatic interaction of Sb3+ and O2- urges the formation of Sb-O-C bonds between Sb2Se3 nanorods and h-rGO. When employed as anode for PIBs, free-standing Sb2Se3@h-rGO electrodes exhibit excellent cycling stability with a high capacity of 382.8 mAh g-1 at 100 mA g-1 after 500 cycles. It is demonstrated that Sb-O-C bonds can dramatically enhance the alloying reaction reversibility, electrochemical kinetics and structural stability of Sb2Se3 nanorods upon cycling.