Synthesis and performance of LiMn0.6Fe0.4PO4/nano-carbon webs composite cathode

LiMn0.6Fe0.4PO4/nano-carbon webs composite cathode material was synthesized by an in situ solid-state reaction at 700 degrees C using polypropylene as the reductive agent and carbon precursor. Pyrolysis of polypropylene at high temperature ensures the purity of LiMn0.6Fe0.4PO4 by in situ introducing the reductive agents of hydrogen and carbon, hinders the growth of LiMn0.6Fe0.4PO4 particles, and would improve the conductivity of the composite by in situ carbon wrapping. Electrochemical tests indicate that this type of composite has an initial discharge capacity of 143 mAh g(-1) with an average discharge voltage of 3.65 V (522 Wh g(-1)) and good cycling stability, which is attributed to the nano-sized carbon webs around LiMn0.6Fe0.4PO4 particles. Cyclic voltammetry tests showed that, the coexistence of Mn2+ with Fe2+ at 4c sites would improve the redox kinetics of Fe3+/F2+ couple in LiMn0.6Fe0.4PO4/nano-carbon webs composite cathode, which is further supported by the electrochemical impedance spectroscopy (EIS). (c) 2005 Elsevier B.V. All rights reserved.