Investigation on a core-shell nano-structural LiFePO4/C and its interfacial C-O interaction

Core-shell LiFePO4/C nanocomposite has been prepared by a sol-gel method. The mean size of the spherical core LiFePO4 is about 30 nm, and thickness of carbon shell is about 3 nm. The bonding character on the interface of core-shell was revealed by soft X-ray absorption spectroscopy (XAS). The as-prepared sample was characterized by X-ray diffraction (XRD), Raman spectrum, Transmission electron microscope (TEM) and High-resolution transmission electron microscopy (HRTEM). Charge-discharge tests show the core-shell LiFePO4/C demonstrates high rate capability (106 mAh g-1 at 20 C) and good cycling performance (negligible capacity loss after 250 cycles).