PPy coated on SiO<inf>2</inf> encapsulated porous carbon nanofibers as a potential anode material for high rate capable and long-life Li-ion battery

Polypyrrole (PPy) coated porous carbon nanofiber-SiO2 composite (PPy/CNF-SiO2) as an anode material has been developed by a simple electrospinning technique followed by pyrolysis process for Li-ion battery. The 1D architecture of porous carbon nanofibers offers a larger electrode/electrolyte interface to promote the charge-transfer reactions and provides sufficient space to buffer a large volume expansion of SiO2, maintaining mechanical integrity of the overall electrode during the lithiation/delithiation process. Moreover, the conducting polymer coating not only improves the electric conductivity of SiO2, but also suppresses the volume expansion and rapid capacity fading caused by serious pulverization. The present anode material shows a remarkable specific reversible capacity of 1070 mA h g−1 at 50 mA g−1 current density and exhibits exceptional discharge rate capability. The cycling stability at high current density of 0.5 A g−1 shows a 100% capacity retention and high coulombic efficiency after 300 charge–discharge cycles. High capacity and high stability makes it a superior anode material for next-generation, high-power, long-life and affordable Li-ion battery.