화학공학소재연구정보센터
Journal of Power Sources, Vol.195, No.19, 6873-6878, 2010
Porous micro-spherical aggregates of LiFePO4/C nanocomposites: A novel and simple template-free concept and synthesis via sol-gel-spray drying method
Porous micro-spherical aggregates of LiFePO4/C nanocomposites were prepared with a process of spray drying at 200 degrees C and subsequent heat treatment at 700 degrees C for 12 h by a novel and simple template-free sol-gel-SD method independent of surfactants or templates. The results indicate that the as-obtained LiFePO4 porous microspheres have the mean diameter of 19.8 mu m, average pore size of 45 nm, and large specific surface area (20.2 m(2) g(-1)) with evenly distributed carbon (4.5 wt.%). The particles can be easily brought into contact with electrolyte, facilitating electric and lithium ion diffusion. They present large reversible discharge capacity of 137.5 mAh g(-1) at the current density of 0.1 C, good rate capacity of 53.8 mAh g(-1) at 10 C, and excellent capacity retention rate closed to 100% after various current densities in the region of 2.0-4.3 V. (C) 2010 Elsevier B.V. All rights reserved.