Research on the Preparation and Sodium-ion Storage Performance of VS₄/rGO Nanocomposites

The size and conductivity of electrode materials play an important role in reaction kinetics of the sodium-ion batteries. VS₄ has high theoretical specific capacity but low conductivity. In order to improve the sodium-ion storage performance of VS₄, VS₄/rGO nanocomposites were prepared by one-step hydrothermal method. The results showed that the specific discharge capacity of VS₄/rGO prepared at 160 °C under hydrothermal condition was 300 mA·h/g after 100 cycles at 0.1 A/g. When the current density was 0.5 A/g, the discharge capacity was 211.4 mA·h/g after 300 cycles. At current densities of 0.1, 0.2, 0.5, 1, 2 and 5 A/g, the discharge specific capacities were 430, 400, 300, 200, 150 and 100 mA·h/g, respectively, showed favorable rate performance. The VS₄/rGO has excellent sodium-ion storage performance due to the synergistic effect between VS₄ nanoparticles and the highly conductive graphene network, which shorted the diffusion path of Na⁺, expanded the contact area between the electrolyte and electrode materials, and improved the electrochemical reaction reversibility of VS₄.