A green and facile approach for hydrothermal synthesis of LiFePO₄ using iron metal directly

Highlights: • LiFePO₄ has been synthesized by a facile hydrothermal method using iron metal directly as an iron source. • Theoretically iron metal delivers 100% atom economy. • The LiFePO₄ electrode demonstrates good electrochemical performance. - Abstract: Hydrothermal LiFePO₄ has been successfully synthesized using iron powder as an iron source and as an in situ reducing agent. The 100% atom economy delivered by iron metal (Fe⁰) makes this process green and inexpensive. A plausible mechanism for the formation of hydrothermal LiFePO₄ powder is also proposed. The structure of the LiFePO₄ powder is well characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. The discharge capacity of the LiFePO₄ electrode is found to be 165 mAh g⁻¹ at 0.1 C-rate, and the cycle-life performance is comparable to the conventionally synthesized LiFePO₄.