Preparation and electrochemical properties of nanoparticle structural LiFePO₄/C by Sol–Gel method as cathode material for lithium ion batteries

In this study, LiFePO₄/C nanocomposites with higher capacity and cycle performance are synthesized by sol–gel method using FeCl₂·4H₂O, H₃PO₄, Li₂CO₃, and Citric acid as the starting materials. LiFePO₄/C cathode materials with different grain size and electrochemical properties were obtained by changing the calcination temperature of LiFePO₄/C precursor prepared by sol–gel method. Specially, the LiFePO₄/C precursor prepared by sol–gel method was heated to 700 °C for 12 h under nitrogen atmosphere, and the nanoparticle structural LiFePO₄/C was obtained. The first discharge specific capacity is 156.5 mAh g⁻¹ at a charging current of 0.2 C. The first discharge specific capacity is 124.5 mAh g⁻¹ at a charging current of 1 C, and after the 250th cycles, the discharge specific capacity is 120.7 mAh g⁻¹, the retention rate of discharge specific capacity is 96.9%.