COMPOSITE MATERIAL BASED ON HARD CARBON AND MOLYBDENUM DISULFIDE AS A NEGATIVE ELECTRODE FOR SODIUM-ION BATTERIES

10.25712/ASTU.1811-1416.2024.04.008

Abstract

In this work, a composite material based on hard carbon fibers modified with molybdenum disulfide nanosheets was prepared using a two-step method. The hard carbon, acts as a substrate, was obtained by heat treatment of viscose fibers at 810 °C. MoS₂ nanoparticles were deposited on fibers by a hydrothermal method. The structure and composition of prepared material were determined using X-ray diffraction, small-angle X-ray scattering, Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, spectrophotometry, and X-ray photoelectron spectroscopy. The electrochemical characteristics of the composite as an anode material for sodium-ion batteries were studied. It was found that due to synergistic effect the composite has advantages over both hard carbon and nanocrystalline MoS₂. As compared to hard carbon, the composite exhibits higher specific capacity even at high current densities. In particularly at 1000 and 2000 mA g^-1, the composite material showed a specific capacity of 139 and 84 mAh g^-1, while hard carbon provides only 73 and 45 mAh g^-1. As compared to MoS₂, the composite demonstrates better cyclability. A significant degradation of sodium storage ability is observed for MoS₂ already after the 90th cycle. In contrast, the composite material remains stable even upon 150-fold cycling with a capacity of 204 mAh g^-1 at 200 mA g^-1.