SnO2 nanoparticles@polypyrrole nanowires composite as anode materials for rechargeable lithium-ion batteries

The SnO2@polypyrrole (PPy) nanocomposites have been synthesized by a one-pot oxidative chemical polymerization method The structure composition and morphology of the as-prepared SnO2@PPy nanocomposites are characterized by XRD FTIR TG SEM and TEM Electrochemical investigations chow that the obtained SnO2@PPy nanocomposites exhibit high discharge/charge capacities and favorable cycling when they are employed as anode materials for rechargeable lithium ion batteries For the SnO2@PPy nanocomposite with 79 wt% SnO2 the electrode reaction kinetics is demonstrated to be controlled by the diffusion of Li+ ions in the nanocomposite The calculated diffusion coefficiency of lithium ions in the SnO2@PPy nanocomposite with 79 wt% SnO2 is 6 7 x 10(-8) cm(2)s(-1) while the lithium-alloying activation energy at 0 5 V is 47 3 kJ mol(-1) which is obviously lower than that for the bare SnO2 The enhanced electrode performance with the SnO2@PPy nanocomposite is proposed to derive from the advantageous nanostructures that allow better structural flexibility shorter diffusion length and easier interaction with lithium (C) 2010 Elsevier B V All rights reserved