Facile synthesis of carbon coated LiFePO4 nanocomposite with excellent electrochemical performance through in situ formed lithium stearate pyrolysis route

Carbon coated LiFePO4 (LiFePO4/C) nanocomposite is successfully synthesized at a comparatively low temperature (400 degrees C) via a pyrolysis process of in situ formed lithium stearate. The obtained products are characterized by X-ray diffraction, electron microscopy, thermogravimetry, infrared and X-ray photoelectron spectroscopy. Experimental results indicate that the in situ formed lithium stearate can decompose at similar to 290 degrees C, which is beneficial for the formation of carbon coating and reduction of Fe3+ species, and then the crystallized LiFePO4/C nanocomposite can be formed at 400 degrees C without other intermediate products. As cathode material of Li-ion battery, the obtained LiFePO4/C nanocomposite exhibits a good rate and cycling performance with a high discharge capacity of similar to 160 mAh g(-1) (>94% theoretical capacity of LiFePO4) at a current density of 1 C (170 mA g(-1)), and similar to 96% of its initial capacity can be retained after 200 charging/discharging cycles. Even at a high current density (10 C), the LiFePO4/C nanocomposite still presents a discharge capacity as high as similar to 100 mAh g(-1). The excellent electrochemical performances of the present LiFePO4/C nanocomposite mainly originate from the good crystallinity, small particles and enhanced electronic conductivity of the materials coated and linked by carbon layers. (C) 2012 Elsevier B.V. All rights reserved.