Hydrothermal preparation and performance of LiFePO₄ by using Li₃PO₄ recovered from spent cathode scraps as Li source

A novel process recycling Li from the spent LiFePO₄ cathode material has been put forward. The new LiFePO₄ sample is synthesized through hydrothermal reaction by using recovered Li₃PO₄ as Li source and FeSO₄·7H₂O as Fe source. The morphologies, structure and physicochemical properties of the re-synthesized LiFePO₄ cathode material were characterized by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurement. The results showed that the morphology and particle size of re-synthesized LiFePO₄ samples become more regular and smaller with the increase of the hydrothermal reaction temperature. Besides, it has been found that the LiFePO₄ cathode material synthesized at 200 °C showed excellent electrochemical properties which deliver a high initial capacity of 144.25 mAh/g at the rate of 1 C and high capacity retention of 96.7% after 200 cycles. Therefore, this work provides a new strategy for recovery and recycle of the spent LiFePO₄ cathode scraps.