Preparation and electrochemical properties of Si0.8Sb/C nanofiber composite anode materials for lithium-ion batteries

The Si0.8Sb/C nanofiber composite anode materials were synthesized with the method of high-energy ball milling combined with electrospinning. The microstructures, morphologies, and electrochemical properties were investigated utilizing X-ray diffraction (XRD), scanning electron microscopy (SEM), constant current charge/discharge tests, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The results indicated that the Si0.8Sb mutually insoluble alloy nanoparticles were coated by the carbon nanofiber. The carbon fiber exhibited high ductility which efficiently improved the cycle performance by reducing the shredding and powdering of anode materials during the volume expansion. The temperature, charge, and discharge cutoff voltage range and current density had an influence on the electrochemical properties and charge/discharge efficiency of Si0.8Sb/C electrode material. The electrochemical performance was optimal when the mass ratio of Si0.8Sb and polyacrylonitrile (PAN) was 3:5. Its initial charge/discharge was 1128.9 mAh/g, and the initial efficiency was 67.6%. After 100 cycles of charge and discharge, a capacity of 510.7 mAh/g and capacity retention of 66.9% were kept, displaying good electrochemical performance.