High‐Stability of Heterostructured Bi2S3/VS4/rGO Anode Enabled by Electrolyte Optimization for Fast‐Charging Sodium‐Ion Batteries

Abstract

Sodium‐ion batteries are attracting great attention as an alternative to lithium‐ion batteries due to the lower cost and better sustainability of sodium. Although the metal sulfide‐based anodes demonstrate much higher theoretical capacity than the hard carbon anodes, the severe capacity degradation and inferior rate capability caused by poor electrical conductivity and sluggish kinetics hinder their applications. Herein, a novel bimetallic sulfide‐based anode wrapped by reduced graphene oxide (i.e., Bi2S3/VS4/rGO) is presented, in which the heterointerfaces between Bi2S3 and VS4 are well distributed among the composite, leading to the promoted charge transfer and the improved Na+ transport kinetics. Combined with electrolyte optimization, the Bi2S3/VS4/rGO demonstrates excellent electrochemical performance, including excellent rate capabilities over 10 A g−1, and a long lifespan over 1000 cycles. This work indicates the significance of the synergistic effect of structure regulation and electrolyte optimization for achieving fast‐charging performance.

Keywords

• anodes
• electrolytes
• heterostructures
• metal sulfides
• sodium-ion batteries