Synthesis and comparative performance study of crystalline and partially amorphous nano-sized SnS2 as anode materials for lithium-ion batteries

Abstract

A facile, time effective, and energy efficient precipitation reaction method was developed to synthesize amorphous/nano crystalline SnS2 using SnCl4·5H2O and thioacetamide (C2H5NS) as Sn and S sources, respectively. As a comparison, nano-crystalline SnS2 was also synthesized via the already established hydrothermal method using the same Sn- and S precursors. The crystal structure, chemical composition, and morphology of both obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The electrochemical performance properties of the as-synthesized SnS2 samples were investigated using galvanostatic cycling with potential limitation, cyclic voltammetry, electrochemical impedance spectroscopy and electrochemical in-situ dilatometry. The results show that SnS2 prepared via the precipitation reaction method electrochemically outperforms that from the hydrothermal method. This is due to the formation of thicker Li2S layers on the particle surfaces, which drastically limits the volume expansion of the Sn particles during the alloying reaction with lithium.