Hydrothermal Process Synthesizing of LiFePO4 with High-rate Capability and High Tap Density

Abstract—LiFePO4/C microspheres were synthesized by a rheological phase method using nanoplates assembled quasi-microspheres of FePO4·2H2O as raw materials, and the FePO4·2H2O precusors were synthesized via a hydrothermal process. The FePO4·2H2O precursors were characterized by XRD and SEM, and the LiFePO4/C were characterized by XRD, SEM, TEM, and charge-discharge test. The LiFePO4/C, with ~2 nm thick amorphous carbon layer coating at the surface, showed excellent high-rate performance: the discharge capacities reaching 116, 96 and 75 mAh g-1 at 10 C, 20 C and 30 C current rates, respectively. Moreover, the LiFePO4/C had a high tap density (1.4 g cm-3). Therefore, this material can be the cathode material for large-scale applications. Keywords-LiFePO4/C; FePO4·2H2O; High-rate performance; High tap density; Lithium ion batteries. I