Synthesis of LiFePO ₄ using FeSO ₄ ·7H ₂ O byproduct from TiO ₂ production as raw material

As the byproduct of TiO 2 industrial production, impure FeSO 4 ·7H 2 O was used for the synthesis of LiFePO 4 . With the purified solution of FeSO 4 ·7H 2 O, FePO 4 · x H 2 O was prepared by a normal titration method and a controlled crystallization method, respectively. Then LiFePO 4 materials were synthesized by calcining the mixture of FePO 4 · x H 2 O, Li 2 CO 3 , and glucose at 700°C for 10 h in flowing Ar. The results indicate that the elimination of FeSO 4 ·7H 2 O impurities reached over 95%, and using FePO 4 · x H 2 O prepared by the controlled crystallization method, the obtained LiFePO 4 material has fine and sphere‐like particles. The material delivers a higher initial discharge specific capacity of 149 mAh·g −1 at a current density of 0.1C rate (1C = 170 mA·g −1 ); the discharge specific capacity also maintains above 120 mAh·g −1 after 100 cycles even at 2C rate. Thus, the employed processing is promising for easy control, low cost of raw material, and high electrochemical performance of the prepared material.