Recycling of waste plastics and scalable preparation of Si/CNF/C composite as anode material for lithium-ion batteries

An economical and practical strategy is proposed for preparation of silicon/carbon nanofibers/carbon (Si/CNF/C) composite for lithium-ion batteries using self-prepared micron-sized silicon and waste high-density polyethylene (HDPE) as raw materials. The obtained Si/CNF/C composite is characterized by SEM, TGA, and XRD, as well as electrochemical characterization. Through a simple pyrolysis approach, pyrolyzed carbon and carbon nanofibers are obtained which acts as a carbon-conductive network and restrains the volumetric expansion of Si during Li-ion insertion/deinsertion processes. The obtained Si/CNF/C composite possesses high initial coulombic efficiency of 82.2% and a steady reversible capacity of 937 mAh g−1 (1685 mAh g−1 based on Si) after 100 cycles at a current density of 100 mA g−1. The strategy proposed here provides a novel way to synthesize high value-added nanocarbon materials for LIBs by reutilization of waste plastics.