Physical and electrochemical properties of LiFePO4 nanoparticles synthesized by a combination of spray pyrolysis with wet ball-milling

Abstract

A novel preparation technique was developed to synthesize LiFePO nanoparticles through a combination of spray pyrolysis (SP) with wet ball-milling (WBM). Using this technique, the preparation of LiFePO nanoparticles was investigated for a wide range of process parameters such as ball-milling time and sintering temperature. The effect of process parameters on the physical and electrochemical properties of LiFePO was then discussed through analysis using by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the Brunauer-Emmet-Teller (BET) method, Raman spectroscopy and using an electrochemical cell of Li|1 M LiClO in EC:DEC = 1:1|LiFePO. LiFePO nanoparticles with a geometric mean diameter of 58 nm were prepared at a rotating speed of 800 rpm and a ball-milling time of 12 h in an Ar atmosphere followed by heat treatment at 500 °C for 4 h in a N + 3% H atmosphere. The sample delivered first discharge capacities of 164 and 100 mAh g at charge-discharge rates of 0.1 and 10 C in the test cells, respectively. The electrochemical properties of LiFePO nanoparticles were strongly affected by the formation of FeP, FeP and α-FeO at higher charge-discharge rates