Synthesis of LiFePO 4/C composite with high-rate performance by starch sol assisted rheological phase method

Abstract

LiFePO 4/C composite was synthesized at 600 °C in an Ar atmosphere by a soluble starch sol assisted rheological phase method using home-made amorphous nano-FePO 4 as the iron source. XRD, SEM and TEM observations show that the LiFePO 4/C composite has good crystallinity, ultrafine sphere-like particles of 100–200 nm size and in situ carbon. The synthesized LiFePO 4 could inherit the morphology of FePO 4 precursor. The electrochemical performance of the LiFePO 4 by galvanostatic cycling studies demonstrates excellent high-rate cycle stability. The Li/LiFePO 4 cell displays a high initial discharge capacity of more than 157 mAh g −1 at 0.2C and a little discharge capacity decreases from the first to the 80th cycle (>98.3%). Remarkably, even at a high current density of 30C, the cell still presents good cycle retention.