Constructing Sb-O-C Bond to Improve the Alloying Reaction Reversibility of Free-Standing Sb <sub>2</sub>Se <sub>3</sub> Nanorods Anode for Potassium-Ion Batteries

Sb 2 Se 3 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 Sb 2 Se 3 nanorods supported by holey rGO composite membranes (Sb 2 Se 3 @h-rGO) are prepared by a direct vacuum filtration and subsequent reduction process, where the pre-electrostatic interaction of Sb 3+ and O 2- urges the formation of Sb-O-C bonds between Sb 2 Se 3 nanorods and h-rGO. When employed as anode for PIBs, free-standing Sb 2 Se 3 @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 Sb 2 Se 3 nanorods upon cycling.