Bi₂S₃/C nanorods as efficient anode materials for lithium-ion batteries

Bi₂S₃ is a promising negative electrode material for lithium storage owing to its high theoretical capacity. Nevertheless, the capacity of Bi₂S₃ decays very rapidly upon Li cycling. Here, Bi₂S₃ and Bi₂S₃/C were successfully synthesized by a novel route. Sulfur powder as a kind of sulfur source reacted with a metal organic framework based on bismuth and trimesinic acid-Bi(BTC)(DMF)·DMF·(CH₃OH)₂ (denoted as Bi-BTC). Trimesic acid further acted as a new type of carbon source to synthesize the Bi₂S₃/C composite. The particle sizes of the composite were smaller than those of pure Bi₂S₃, showing the suppression of Bi₂S₃ aggregation. Charge-discharge performance and cyclability for both the Bi₂S₃ and Bi₂S₃/C composites in lithium-ion batteries were measured. Specifically, the specific capacities of Bi₂S₃/C and Bi₂S₃ reached 765 and 603 mA h g⁻¹, respectively, at 100 mA g⁻¹ after 100 cycles. Because of its high capacity and excellent cycle life, Bi₂S₃/C is a promising energy storage material.