Carbon coated Bi2S3 microwires as anode for enhanced lithium storage

Abstract

As a typical metal sulfide, Bi2S3 is intensively explored for its high capacity. However, the capacity decays quickly because of its intrinsic poor conductivity and huge volume variation. Therefore, carbon coated Bi2S3 microwires (Bi2S3@C) are synthesized via facile hydrothermal and subsequent annealing procedure to improve lithium storage. The composite manifests a high capacity of 661 mAh g−1 at 0.1 A g−1 after 100 cycles. It exhibits excellent rate capability, delivering the capacity of 757 mAh g−1 at 0.1 A g−1 and 331 mAh g−1 even at the high current density of 10 A g−1. The composite also shows good cycling stability. It delivers a high capacity of 456 mAh g−1 at 2 A g−1 after 1000 cycles. The good lithium storage capability is ascribed to the synergistic effect of dwindled size and amorphous carbon coating layer. The carbon layer not only improves the electronic conductivity but also relaxes the strain upon cycling.