Sea urchin-inspired preparation of SnO2@MoS2 heterostructures for enhanced sodium storage

Abstract

Molybdenum disulfide (MoS 2 ) has garnered significant interest as an anode candidate for sodium-ion batteries, attributed to its high theoretical capacity and distinctive layered architecture. Nevertheless, sluggish Na + diffusion kinetics during cycling restrict its practical viability. Heterostructure engineering has proven to be an effective approach to improve the electrochemical property of electrode. Herein, sea urchin-inspired preparation of flower-like MoS 2 nanosheets grown on hollow double-shelled SnO 2 nanospheres (H-SnO 2 @MoS 2 ) was designed for high-efficiency sodium storage. The interfacial built-in electric field is generated between the MoS 2 -SnO 2 heterointerface, which reduces the diffusion barrier for Na + and enhances the ion-storage kinetics. Besides, the sea urchin-like heterostructure can effectively alleviate volume expansion of the electrode during operation, thereby enhancing cycle stability. Hence, the H-SnO 2 @MoS 2 composite delivers an impressive reversible capacity of 455 mAh g −1 at 100 mA g −1 after 50 cycles and exhibits superior rate capabilities of 350.5 mAh g −1 at 2000 mA g −1 as an anode for sodium ion storage.