Physical and electrochemical characterizations of LiFePO 4-incorporated Ag nanoparticles

Abstract

Olivine-type LiFePO 4 composite materials for cathode material of the lithium-ion batteries were synthesized by using a sol-gel method and were coated by a chemical deposition of silver particles. As-obtained LiFePO 4/C-Ag (2.1 wt.%) composites were characterized by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), conductivity measurements, cyclic voltammetry, as well as galvanostatic measurements. The results revealed that the discharge capacity of the LiFePO 4/C-Ag electrode is 136.6 mAh/g, which is 7.6% higher than that of uncoated LiFePO 4/C electrode (126.9 mAh/g). The LiFePO 4/C coated by silver nanoparticles enhances the electrode conductivity and specific capacity at high discharge rates. The improved capacity at high discharge rates may be attributed to increased electrode conductivity and the synergistic effect on electron and Li + transport after silver incorporation. © 2010 Springer-Verlag.