Size-Controlled Synthesis of LiFePO4/C Composites as Cathode Materials for Lithium Ion Batteries

Nano-micro-structured spherical LiFePO4/C composite is synthesized via a ball-milling-assisted spray-drying method. SEM characterization demonstrates that the primary and secondary particle sizes are on the order of several hundred nanometers and approximately fifteen microns. The primary particles are successfully controlled through homogenous milling with a narrow particle size distribution. Herein, LiFePO4/C composites with a primary particle (i.e., 200 nm and 400 nm in diameter) are prepared. The relationship between electrochemical performance and particle size is evaluated using both half- and full-cell tests. The results demonstrate that the 200 nm diameter sample has a better rate capability and low-temperature performance, whereas the 400 nm sample is better at cycling.