Amorphous/crystalline heterostructured indium (III) sulfide/carbon with favorable kinetics and high capacity for lithium storage

Abstract

Abstract Nanostructured metal sulfides (MSs) are considered as prospective anodes for Li ion batteries (LIBs) due to their high specific capacity and abundant raw materials on Earth. Nerveless, the poor conductivity and volume expansion hinder their application. Here, we report the design of carbon coated indium sulfides nanotubes, where MIL-68 (In) metal-organic frameworks (MOF) as a precursor to generate In2S3/carbon (In2S3/C) through a solvothermal process. The construction of amorphous/crystalline structure not only combines the advantages of abundant ion channels of amorphous structure, but also has high crystal conductivity and promotes ion transport. The In2S3/C anode of LIBs exhibits excellent performance of 835 mAh·g− 1 at the current density of 0.5 A·g− 1 after 500 cycles. In2S3/C also shows outstanding long-term performance with 717 mAh·g− 1 at 2 A·g− 1. Through the kinetic analysis and ex situ XPS analysis, the lithium storage mechanism is realized. Further density functional theory (DFT) calculations indicate that In2S3/C electrodes have low adsorption energies and fast diffusion kinetics. In a word, the MOF-derived In2S3/C exhibits better electrochemical performances than commercial In2S3. This research will inspire the exploration of MSs as well as detect potential “diamonds in the rough”.