Two-dimensional SnS2@PANI nanoplates with high capacity and excellent stability for lithium-ion batteries

Abstract

Nanostructured electrode materials have been extensively studied with the aim of enhancing lithium ion and electron transport and lowering the stress caused by their volume changes during the charge–discharge processes of electrodes in lithium-ion batteries. In this work, novel two-dimensional nanocomposite, polyaniline-coated SnS₂ (SnS₂@PANI) nanoplates have been prepared by an in situ oxidative polymerization of aniline on the surface of ultrasonic exfoliated SnS₂ nanoplates. The SnS₂@PANI nanoplates present a lamellar sandwich nanostructure, which can provide a good conductive network between neighboring nanoplates, shorten the path for ion transport in the active material, and alleviate the expansion and contraction of the electrode material during charge–discharge processes, leading to improved electrochemical performance. As an anode material for lithium-ion batteries, SnS₂@PANI nanoplates have a high initial reversible capacity (968.7 mA h g⁻¹), excellent cyclability (730.8 mA h g⁻¹ after 80 cycles, corresponding to 75.4% of the initial reversible capacity), and an extraordinary rate capability (356.1 mA h g⁻¹ at the rate of 5000 mA g⁻¹). This study not only provides a simple and efficient synthesis strategy for various inorganic–organic composites obtained by the exfoliation of layered inorganic materials, but can also help in the design of novel, high performance electrode materials.