High-Performance Realized in Earth Abundant Bi2s3 Anode for Li-Ion Batteries Via Carbon Film In-Situ Encapsulating

Abstract

Bi2S3 with high theoretical capacity has been regarded as a promising anode material. However, a huge capacity decline was detected during discharge process, derived from the disruption of the microstructure and the formation of solid electrolytes interface. In this work Bi2S3@Cppy nanocomposites were rationally designed and synthesized using a facile solvent reaction method followed by polymer-coating and in-situ carbonization strategies. The urchin-like structure combined with nitrogen-doped carbon was available to enhance the conductivity of Bi2S3 and inhibit the volume change, further mitigate the large stresses associated with volume expansion changes in the reaction and ensure that charge transfer kinetics. Eventually, Bi2S3@Cppy has a high reversible specific capacity of 388.1 mAhg-1 after 100 cycles at 0.1 Ag-1, which is five times higher than that of the bare Bi2S3. Besides, the reversible capacity of 363.8 mAhg-1 was obtained after 800 cycles at 0.5 Ag-1. In-situ XRD was used to analyze the mechanism of the Li-ions storage during the charging and discharging. Eventually, a full cell with Li1.2Ni0.13Co0.13Mn0.64O2 cathode and Bi2S3@Cppy anode was fabricated, and a capacity of 100 mAhg-1 was detected after 100 cycles at a current density of 0.05 Ag-1. This pathway is expected to optimize the discharge capacity and cycling stability in other anodes.

Keywords: Bi2S3, carbon composites, electrochemical performance, anodes