Binary transition metal sulfides MoS2–NiS2 anchored on biomass-derived carbon for improved performance of lithium–sulfur batteries

Abstract

The poor electrical conductivity of sulfur and electrochemically active solid-state products (Li2Sn, n = 1–3), and the shuttle effect have led to the low cycling stability of lithium-sulfur batteries and the low utilization of the sulfur cathode. In this work, 3D porous biomass-derived carbon material (KMC) was prepared from Miscanthus sinensis by KOH activation. The transition metal sulfide with excellent adsorption and catalytic characteristics was effectively combined with the conductive porous biomass-derived carbon material, and a KMC/MoS2−NiS2 composite material was obtained. The product was characterized by field emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. Results show that MoS2−NiS2 nanoparticles can be uniformly distributed on the porous carbon material. Electrochemical measurements reveal that with an initial specific capacity of 1292 mA h g–1 at a current density of 0.1 C. After 400 cycles at 0.5 C, the specific capacity of KMC/MoS2−NiS2/S decays from 1007 to 814 mA h g–1. Thus, the capacity decay rate per cycle is about 0.054 %. This strategy provides a new idea for developing lithium−sulfur batteries with attractive performance.