The Electrochemical Behavior of LiFePO₄/C Cathode Materials Doped with Antimony

LiFePO₄ is considered as a practical cathode material because of low raw materials’ cost, excellent thermal safety, environmental friendliness, and long operational life, despite obstacles such as low tap density, low electric conductivity and slow lithium-ion diffusion. To overcome these problems, we used an antimonyion doping method to synthesize LiFePO₄/C with sebacic acid as a carbon source by a high-temperature solid-state reaction method. The effects of antimony concentration, sebacic acid content, calcination temperature, and calcination time on cell performance were investigated. After Sb³⁺ doping, LiFePO₄ was converted to a p-type semiconductor and demonstrated greater electric conductivity of about 10^-3 S cm^-1. The 1.0 mol.% Sb-doped LiFePO₄/C synthesized with 36 wt.% sebacic acid delivered an initial discharge capacity of 154 mAh g^-1 at a 0.2 C-rate between 4.0-2.8 V. The doped cathode materials were further characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), and high-resolution transmission electron microscope (TEM) techniques for structural analysis and confirmation.