One-pot synthesis of graphene/In2S3 nanoparticle composites for stable rechargeable lithium ion battery

Graphene/In₂S₃ nanoparticle composites were synthesized by an easy and scalable hydrothermal method without any surfactant, strong reducing agent or highly toxic hydrazine. Graphene oxide acts as a scaffold for growth of In₂S₃ nanoparticles and was simultaneously reduced to graphene in the growth process of In₂S ₃ nanoparticles. The composites with different mass ratios of graphene were used as anodes in rechargeable lithium ion batteries. Transmission electron microscopy characterization and impedance measurement verified that graphene can act as a buffering layer to accommodate the volume change of In₂S₃ and facilitate the charge-transfer process. The battery with graphene/In₂S₃ nanoparticle composites anode showed a remarkable Li-storage performance with a better cycling life and higher capability than that of the pure In₂S₃. The graphene/In₂S₃ nanoparticle composites retain a high discharge capacity of ∼1000 mA h g^-1 after 200 cycles at a current density of 0.1 A g^-1. Investigation on the changes in morphology, phase, and microstructure of the graphene/In₂S ₃ nanoparticle composite upon cycling indicate that the incorporation of graphene with In₂S₃ can optimize the morphology and phase stability of In₂S₃. It is believed that the scalable preparation process and the respectable electrochemical performance would pave the way for practical application. © 2013 The Royal Society of Chemistry.